In principle, I am suspicious of citations as a measure of importance --- they are affected by so many random factors. I have to concede, however, that there is a pretty good correlation between the most highly cited of my papers and the papers I consider most significant myself, even if the rankings aren't identical. I can thus give a reasonably good guide to my main science contributions by running through a summary of my most highly cited papers, with comments about a few other papers at the end.
I first went through this exercise in October 2010, when it was a list of my 20 most cited papers. When I updated it in 2016 I was reluctant to chop out papers that I had written about previously (and am very fond of!), so I expanded to 25. Now that I'm updating again in 2019, I've decided to adopt a criterion that won't require me to unwrite things I've written: this is a list of my papers with 200 or more ADS citations, ordered with the most highly cited at the top.
But not all of those papers. As a long-time member of the Sloan Digital Sky Survey -- I joined the SDSS as a postdoc in 1992, continued as an external participant after moving to Ohio State in 1995, and became Spokesperson of SDSS-II in 2005 and Project Scientist of SDSS-III in 2007 -- I am a co-author on all of the SDSS data release papers and a number of SDSS technical papers, which collectively dominate the top of my "most cited" list. I have also co-authored many SDSS science papers in which I made a contribution but was not centrally involved in the analysis and writing of the paper. I have omitted all of these from the list below, keeping only those SDSS papers where I played a central role. As of 4/1/2019, this selection gives 40 papers with 200+ citations.
As is immediately evident from this list, I have been very fortunate to work with many terrific collaborators over the years, including a number of great thesis students and postdocs.
Numbers below correspond to the order given by ADS as of 4/1/2019. For those who like h-indices, mine (as of 4/1/19) is 127 if you include all of the SDSS papers, or 90 if you omit SDSS papers in which I am not among the first four authors.
Enough preamble, here is the list:
1. How do galaxies get their gas?
D. Keres,
N. Katz,
D. H. Weinberg,
R. Davé
2005, MNRAS, 363, 2
This paper uses cosmological smoothed particle hydrodynamics (SPH)
simulations to argue that galaxies gain a large fraction of their
mass by "cold mode accretion" of gas that was never shock heated
near the virial temperatures of their parent halos, and that this
cold accretion occurs preferentially along filamentary structures
feeding low mass (< 1012Msun) halos.
One can find precedents for this idea in many earlier analytic
papers (as far back as
Binney 1977) and numerical simulation papers, including
some of our own. Nonetheless, it was the Keres et al. paper
and the contemporaneous papers by Birnboim and Dekel
(2003,
2006)
using high-resolution 1-D simulations that really put "cold accretion"
on the map as a key element in understanding the physics of
galaxy formation. While this phenomenon is by now robustly
established in numerical simulations, the observational evidence
for it remains circumstantial.
2. Spectroscopic Target Selection in the Sloan Digital Sky Survey:
The Main Galaxy Sample
M. Strauss,
D. H. Weinberg,
R. H. Lupton,
V. K. Narayanan,
J. Annis,
M. Bernardi,
et al.
2002, AJ, 124, 1810
Despite the qualification above, the second paper on my list is in fact
an SDSS technical publication. My most important technical
contribution to the original SDSS was my role in designing
and testing (on simulated data and, eventually, on real data)
the selection criteria for the main spectroscopic galaxy sample.
If you hate Petrosian magnitudes, you largely have me (and Petrosian)
to blame.
3. SDSS-III: Massive Spectroscopic Surveys of the Distant Universe,
the Milky Way, and Extra-Solar Planetary Systems
D. J. Eisenstein,
D. H. Weinberg,
E. Agol,
H. Aihara,
C. Allende Prieto,
S. F. Anderson,
et al.
2011, AJ, 142, 72
This paper presents an overview of the SDSS-III program and
its four component surveys: the BOSS survey of the distant
universe aimed at precision cosmological measurements,
the SEGUE and APOGEE surveys of the structure and chemical
evolution of the Milky Way, and the MARVELS search for
extra-solar planets. While the surveys and the tools that
enabled them were individually described in many further technical
articles, this paper gave a high-level overview of the full
project in the early stages of its execution, analogous to the
York et al.
paper for SDSS-I (which is, as it happens, the most highly
cited paper I have co-authored, by a good margin).
One of the most important contributions of my career has been
serving as Project Scientist of SDSS-III, which in practice has
meant a myriad of interestingly varied tasks related to the design,
organization, promotion, and execution of the project.
One of those tasks was to spearhead the organization and writing
of this paper, though Daniel is rightly the first author in recognition
of his indispensable and superb work as SDSS-III Director.
4. Cosmological Simulations with TreeSPH
N. Katz,
D. Weinberg,
L. Hernquist
1996, ApJS, 105, 19
The Keres et al. paper is a recent installment of a program that
Lars Hernquist, Neal Katz, and I began in the early 1990s, using
SPH simulations to model the formation of galaxies and evolution
of the intergalactic medium (IGM) in cold dark matter cosmological
models. This paper describes our numerical methods for these
simulations and presents numerous illustrations and tests.
It therefore underpins many of our own papers, and it has been
a useful reference point for many subsequent efforts in
cosmological hydrodynamics, especially for its discussions of
gas cooling, photoionization, and star formation.
In more recent years, Neal and I have continued this program in collaboration with Romeel Davé and many others, while Lars has continued in collaboration with Volker Springel and many others.
5. Observational probes of cosmic acceleration
D. H. Weinberg,
M. J. Mortonson,
D. J. Eisenstein,
C. Hirata,
A. G. Riess,
E. Rozo
2013, Physics Reports, 530, 87-255
This article presents a book-length review of the observational
and experimental methods being used to probe the origin of cosmic
acceleration. It is oriented towards the goals and capabilities
of "Stage III" and "Stage IV" dark energy experiments,
which include some of the most ambitious cosmological survey projects
now being undertaken around the world.
After historical and scientific introduction that are intended to
make it accessible to any reader who has taken a graduate cosmology course,
it provides detailed discussion of theoretical background,
observational strategies, statistical errors, and systematic
uncertainties for each of the major experimental methods.
A central theme of the review is the complementarity of
different methods, including extensive forecasts of how they
work together and the levels of precision required to remain
competitive. I was fortunate to assemble an all-star cast of co-authors
for this review, and I think we all learned a lot from each
other over the three years it took us to complete it.
As a work of scientific literature, it is probably the best
thing I have written.
With Michael Mortonson and Martin White, I have written a (much) shorter review with more focus on recent observational results, for the Particle Data Group Review of Particle Physics. This review is updated every 2 years; the most recent version is available here.
6. Reionization and the Abundance of Galactic Satellites
J. S. Bullock,
A. V. Kravtsov,
D. H. Weinberg
2000, ApJ, 539, 517
In 1999,
Moore et al.
and
Klypin et al.
showed that the cold dark matter scenario generically predicts
an enormous population of low mass subhalos within the Milky Way
halo, far exceeding the known population of Galactic satellites.
This paper proposed a potential solution to this
"missing satellite problem": that gas accretion was suppressed
in low mass halos by photoionization heating, and that the
observed satellites were those that accreted a significant
fraction of their mass before reionization. The full explanation
of the relation between dark matter subhalos and Galactic
satellites is still a matter of debate, but it is now widely
believed that the resolution to this puzzle lies in baryonic physics
rather than dark matter physics, and (somewhat less) widely
believed that photoionization is the critical mechanism that
suppresses the luminosity of the low mass subhalos.
This paper relies heavily on Thoul & Weinberg 1996,
described below.
More recently,
Koposov et al. 2009
revisited this model in the light of improved numerical
underpinnings and, more importantly, the ultra-faint dwarf
satellite population discovered by the SDSS.
7. The Halo Occupation Distribution: Toward an Empirical Determination
of the Relation between Galaxies and Mass
A. A. Berlind,
D. H. Weinberg
2002, ApJ, 575, 587
This paper, based on work in Andreas Berlind's PhD thesis,
proposed to model the relation between galaxies and dark matter
in terms of the probability distribution P(N|M) of finding
N galaxies of a given type in a halo of virial mass M, together
with prescriptions specifying the relative spatial and velocity
distributions of galaxies and dark matter within these halos.
The direct inspiration for our paper came from
Benson et al. (2000),
but a number of groups coming at the problem of matter clustering
and galaxy bias from different directions had proposed closely related
ideas, including
Kauffmann et al. 1997
,
Jing, Mo & Borner 1998
,
Ma & Fry 2000
,
Peacock & Smith 2000
,
Seljak 2000
,
and
Scoccimarro et al. 2001
.
The distinctive strengths of our paper, I think, were to present
halo occupation statistics as a general tool for modeling galaxy
bias and to lay out a general strategy for using this tool both
to infer relations between galaxies and dark matter and to
sharpen cosmological parameter constraints. Reflecting this
philosophy, we introduced the now widely used term
"halo occupation distribution" or "HOD".
We used N-body simulations to show how a variety of galaxy clustering
statistics depended on different features of the HOD, with
particular attention to the HOD properties required to obtain
a nearly power-law two-point correlation function.
8. Baryons in the Warm-Hot Intergalactic Medium
R. Davé,
R. Cen,
J. P. Ostriker,
G. L. Bryan,
L. Hernquist,
N. Katz,
D. H. Weinberg,
M. L. Norman,
B. O'Shea
2001, ApJ 552, 473
In hydrodynamic cosmological simulations, much of the low-redshift
IGM is comprised of gas at moderate densities and temperatures
of 105K < T < 107K, which is very
difficult to detect.
Cen & Ostriker (1999)
labeled this gas the warm-hot intergalactic medium,
a clunky term with a catchy acronym.
This paper used three different numerical codes to demonstrate
the robustness of WHIM predictions, showing that it should contain
30-40% of the baryons in the present-day universe.
This prediction has inspired numerous observational programs
using UV spectroscopy, X-ray spectroscopy, and soft X-ray emission
to try to find these "hidden" baryons.
9. The Luminosity and Color Dependence of the Galaxy Correlation Function
I. Zehavi,
Z. Zheng,
D. H. Weinberg,
J. A. Frieman,
A. A. Berlind,
M. R. Blanton,
et al.
2005, ApJ, 630, 1
This paper analyzed a redshift sample of about 200,000 SDSS galaxies,
focusing on the projected two-point correlation function of subsamples
defined by cuts in luminosity and color. In addition to providing
some of the best measurements of these trends
(with the other best measurements coming from the analyses of the
2dF Galaxy Redshift Survey by
Norberg et al. 2001
and
Norberg et al. 2002
), this paper pioneered the use of Halo Occupation Distribution
(HOD) modeling to interpret these trends in terms of the relations
between galaxy properties and the masses of their host dark matter
halos (see Berlind et al. 2002 and
Zheng et al. 2005
below). From the measurements and modeling, we concluded that the
luminosity dependence of clustering arose mainly from the trend of
increasing halo mass with increasing luminosity for central galaxies,
while the color dependence was strongly affected by the
larger fraction of red galaxies that were satellite systems in massive
halos. We also found a roughly constant ratio of 23 between the
minimum halo mass required to host a central galaxy above a
luminosity and the halo mass required to host, on average, one
satellite galaxy above the same threshold. This rather large gap,
a consequence of the rarity of near-equal mass halo mergers, has
profound effects on galaxy clustering. We carried out
a major update of this work using the final SDSS-II data set (DR7)
and taking advantage of subsequent improvements in modeling
methods in
Zehavi et al. 2011.
10. Galaxy Clustering in Early Sloan Digital Sky Survey Redshift Data
I. Zehavi,
M. R. Blanton,
J. A. Frieman,
D. H. Weinberg,
H. J. Mo,
M. A. Strauss,
et al.
2002, ApJ, 571, 172
This paper presented the first measurements of galaxy clustering from
the SDSS redshift survey, specifically the two-point correlation function
for a sample of about 30,000 galaxies from
the early data release. While there were no hugely surprising results,
the measurements showed very clearly the small and large scale signatures
of redshift-space distortions induced by galaxy peculiar velocities,
the difference in real-space and redshift-space clustering between
red and blue galaxies, and scale-independent luminosity bias
large separations. It established the basic tools and methodology
for subsequent analyses of larger samples (e.g.,
Zehavi et al. 2005), which led to a number
of novel results.
11. Galaxies in a simulated ΛCDM Universe - I. Cold mode and hot cores
D. Keres,
N. Katz,
M. Fardal,
R. Davé,
D. H. Weinberg
2009, MNRAS, 395, 160
This paper is a follow-up of Keres et al. 2005,
investigating cold and hot accretion in SPH simulations that
had 10 times larger volume than our 2005 simulations
and used a different code (Volker Springel's GADGET) with
a different implementation of the SPH equations.
This study confirmed two key results of the 2005 paper,
the major role of cold accretion and the transition to hot
gas halos at a dark matter halo mass of roughly 5e11 solar masses,
and it provided much better quantification of the evolution
of accretion rates onto central and satellite galaxies.
The main difference from 2005 was the formation
of cores in the hot gas halos of the GADGET simulations leading
to much lower rates of hot gas accretion onto galaxies.
This difference appears to arise from the difference in the
SPH formulations. While a range of numerical methods
(SPH, adaptive grid codes, moving mesh grid codes) over a
wide range of resolution all agree on the dominance of cold
accretion in low mass halos and a transition to shocked gas halos
at high masses, they give widely differing predictions for the
amount hot gas that cools onto galaxies.
This is probably the largest numerical uncertainty in "weak feedback"
simulations of galaxy formation, though the implementation of
galactic winds powered by star formation or AGN feedback
ultimately has a larger impact on predicted galaxy properties.
12. Theoretical Models of the Halo Occupation Distribution:
Separating Central and Satellite Galaxies
Z. Zheng,
A. A. Berlind,
D. H. Weinberg,
A. J. Benson,
C. M. Baugh,
S. Cole,
R. Davé,
C. S. Frenk,
N. Katz,
C. G. Lacey
2005, ApJ, 633, 791
This paper re-examined theoretical predictions of the
halo occupation distribution in SPH simulations and semi-analytic
models of galaxy formation, first undertaken by
Berlind et al. 2003.
Here we revisited these models models in light of the HOD
description proposed by
Kravtsov et al. 2004
based on dark matter subhalos.
We found that this description also applied well to our
SPH and semi-analytic galaxy populations: the HOD for galaxies
above a mass or luminosity threshold is well
characterized as the sum of a step-function like component
for central galaxies and a power-law component (approximately
linear) for satellite galaxies, with the two components offset
in mass by a roughly constant factor. We also showed that
the conditional luminosity function (see
Yang, Mo, & van den Bosch 2003
), the distribution of galaxy luminosities in halos of fixed mass,
is well described by the sum of a log-normal component for the
central galaxy and a truncated
Schechter
function for the satellites, with the global Schechter
function emerging only when one sums over the halo population.
There was a nice synergy between this theory paper and
the contemporaneous Zehavi et al.
SDSS paper: when modeling the luminosity and color dependence
of the SDSS galaxies, we found that we needed better theoretical
models to motivate our parameterizations, and once we developed
these improved theoretical models, we found that several trends
that had seemed surprising or puzzling in the data were in
fact natural predictions of the theory.
The HOD parameterizations proposed in this paper are widely used
in analyses of observed galaxy clustering and creation of mock
catalogs from simulations.
13. Galaxy Clustering in the Completed SDSS Redshift Survey:
The Dependence on Color and Luminosity
I. Zehavi,
Z. Zheng,
D. H. Weinberg,
M. R. Blanton,
N. A. Bahcall,
A. A. Berlind,
et al.
2011, ApJ, 736, 59
As mentioned previously in the discussion of
Zehavi et al. 2005,
this paper brings to completion the program of measuring the
luminosity and color dependence of the galaxy correlation function
in the
SDSS Main Galaxy Sample,
this time from the final data release of SDSS-II (DR7),
and interpreting the measurements via HOD modeling.
Because of the data set and the modeling techniques, it has
become the standard reference on the HODs of different classes
of galaxies (especially luminosity-thresholded samples) in the
present-day universe. I find myself referring to its Table 3
(and to a lesser extent Table 2) constantly.
14. The Lyman-Alpha Forest in the Cold Dark Matter Model
L. Hernquist,
N. Katz,
D. H. Weinberg,
J. Miralda-Escudé
1996, ApJ, 457, L51
This paper, alongside earlier papers by
Cen et al. 1994
and
Zhang, Anninos & Norman 1995
,
transformed the understanding of the Lyman-alpha forest by
showing that it was naturally predicted in hydrodynamic simulations
of the CDM cosmological model, as quasar lines of sight traversed
the photoionized intergalactic medium and intersected concentrations
of neutral hydrogen. While our paper was the third of this group,
I think it was particularly influential for advancing the view
that the low column density Lyman-alpha forest could really be
regarded as a form of the
Gunn-Peterson effect
arising in a smoothly fluctuating, continuous medium, a view
that we developed quantitatively in subsequent work and is now
well established. We also pointed out that for standard estimates
of the photoionizing background intensity, explaining the observed
opacity of the forest required a baryon density at the high end
of then-current estimates.
(For closely related arguments from an analytic or semi-analytic
point of view, see
Rauch & Haehnelt 1995,
Bi & Davidsen 1997,
and
Hui, Gnedin, & Zhang 1997
, which are among my favorite Lyman-alpha forest papers.)
15. The Low-Redshift Lyman-Alpha Forest in Cold Dark Matter Cosmologies
R. Davé,
L. Hernquist,
N. Katz,
D. H. Weinberg
1999, ApJ, 511, 521
This paper extended our numerical studies of the Lyman-alpha forest
to low redshift, comparing to observations from Hubble Space Telescope.
In addition to showing generally good agreement with these observations,
we established several key features of IGM evolution:
(1) evolution of the Lyman-alpha forest slowed at low redshift as
decreasing UV background intensity began to compete with decreasing
mean density from cosmic expansion;
(2) the mapping between Lyman-alpha column density and gas overdensity
shifted at lower redshifts, so that typical 1014 cm-2
absorbers at high z were analogous to weaker 1013 cm-2
absorbers at low z, and the typical absorbers found in low redshift searches
were analogous to strong absorbers at high redshift, explaining their
stronger correlations with galaxies;
(3) at z < 1, a substantial fraction of the IGM is shock heated
to temperatures T > 105K and compressed to moderate
overdensities (10-100), the component now usually referred to as the
WHIM (see Dave et al. 2001 above),
though the unshocked, diffuse medium remains a major
baryonic component and produces most Lyman-alpha forest absorption.
An update of this paper that draws on better simulations and observational
lessons learned in the ensuing decade can be found in
Davé et al. 2010.
16. Hydrodynamic Simulations of Galaxy Formation.
II. Photoionization and the Formation of Low-Mass Galaxies
A. Thoul,
D. H. Weinberg
1996, ApJ, 465, 608
This paper used 1-dimensional, spherically symmetric simulations
of the collapse of density peaks to investigate the impact of
a photoionizing background on the formation of low mass galaxies.
We included both collisionless dark matter and baryonic matter
with a full treatment of photoionization and radiative cooling.
We found that photoionization suppresses formation of galaxies
(more precisely, cooled baryonic components) in halos with
circular velocity Vc < 30 km/s and has little impact
on halos with Vc > 75 km/s, with a steady trend in
between. In a cute experiment, we carried out simulations with
suppressed cooling but no heating and with heating but unsuppressed
cooling to demonstrate that heating of the gas near turnaround
was the dominant effect, making the scale of suppression higher
than one might naively expect for 104K gas.
Recent work using very high resolution 3-d simulations has
largely held up this paper's basic results, but it has shifted
the characteristic suppression scale somewhat lower, to ~ 25 km/s
(Hoeft et al.
2006,
Okamoto et al. 2008
).
17. The Opacity of the Ly alpha Forest and Implications for
OmegaB and the Ionizing Background
M. Rauch,
J. Miralda-Escudé,
W. L. W. Sargent,
T. A. Barlow,
D. H. Weinberg,
L. Hernquist,
N. Katz,
R. Cen,
J. P. Ostriker
1997, ApJ, 489, 7
This paper drew on the numerical simulations described above
(under Hernquist et al. 1996)
and on a set of high-resolution
Keck Lyman-alpha forest spectra by Rauch, Sargent, and Barlow
to infer lower limits on the mean baryon density. The mean opacity
of the forest depends on the baryon density (squared) divided by
the photoionization rate from the UV background. A lower limit
on the latter from the quasar luminosity function then leads to
a lower limit on the former, but it requires both a measurement
of the mean opacity and a theoretical model of the forest.
(However,
Weinberg et al. 1997 showed that the conclusion depends on
the general features of the model rather than the fine details,
making it insensitive to imperfections in the numerical simulations.)
At the time of this paper, two
groups were getting quite different estimates of the primordial
deuterium abundance from Keck spectra, a "high" deuterium abundance
implying (via big bang nucleosynthesis) a low baryon density and a
"low" deuterium abundance implying a high baryon density.
Our paper provided a strong argument for the low deuterium/high baryon
density solution, which has been borne out by subsequent observations.
18. Toward a Precise Measurement of Matter Clustering: Lyman-alpha
Forest Data at Redshifts 2-4
R. A. C. Croft,
D. H. Weinberg,
M. Bolte,
S. Burles,
L. Hernquist,
N. Katz,
D. Kirkman,
D. Tytler
2002, ApJ, 581, 20
20. Recovery of the Power Spectrum of Mass Fluctuations from Observations
of the Lyman-alpha Forest
R. A. C. Croft,
D. H. Weinberg,
N. Katz,
L. Hernquist
1998, ApJ, 495, 44
It's easiest to discuss these two papers together, slightly out of order.
Building on the "continuously fluctuating medium" view of
the Lyman-alpha forest advocated in
Hernquist et al. 1996
and elaborated in Rauch et al. 1997 and
Croft et al. 1997(on intergalactic helium), the 1998 paper
(listed second)
proposed measuring the 1-dimensional power spectrum of transmitted
flux in Lyman-alpha forest spectra and using it to infer the power
spectrum of the underlying matter distribution. Tests on spectra
from our SPH simulations showed that this technique worked
remarkably well, providing a novel tool to probe matter clustering
in the high-redshift universe. To my knowledge, this paper is the
first journal article with the equation generally known as the
"fluctuating Gunn-Peterson approximation" or FGPA, a term that
I introduced in an earlier
conference proceedings.
Using this approximate physical picture, we argued that the
similarity of shape between the flux and matter power spectra should
be robust and, crucially, that measurements of the mean opacity
of the forest could effectively determine the "bias factor" of
the forest, allowing one to infer the amplitude as well as the
shape of the matter power spectrum.
The 2002 paper applied this technique (with some refinements) to a sample of 30 Keck HIRES spectra (obtained for other purposes) and 23 Keck LRIS spectra (obtained in a one-night observing run specifically for this purpose). We obtained what were then much the strongest constraints on matter clustering at redshift z = 2-4 and derived corresponding constraints on cosmological parameters. Consistency of our constraints with estimates from independent data provided a novel test of the Lambda-CDM scenario (inflationary cold dark matter with a cosmological constant) that was then emerging as the standard cosmological model. These papers, together with Weinberg et al. 1998 (a conference proceedings), Croft et al. 1999, and McDonald et al. 2000 established many of the basic principles of Lyman-alpha forest cosmology that are still being used today. Among other things, they showed that moderate resolution spectra, in large numbers, could provide high-precision cosmological constraints, a key insight underlying analyses of the SDSS Lyman-alpha forest ( McDonald et al. 2005) and the BOSS quasar survey of SDSS-III. Major recent developments in the field include a beautiful high-precision measurement of the 1-d flux power spectrum in the BOSS Lyman-alpha forest ( Palanque-Delabrouille et al. 2014) and the detections of large-scale three dimensional clustering and baryon acoustic oscillations in the BOSS Lyman-alpha forest as reported by Slosar et al. 2011, Busca et al. 2013, Slosar et al. 2013, and Delubac et al. 2014.
19. Black Hole Masses and Eddington Ratios at 0.3 < z < 4
J. A. Kollmeier,
C. A. Onken,
C. S. Kochanek,
A. Gould,
D. H. Weinberg,
M. Dietrich,
R. Cool,
A. Dey,
D. J. Eisenstein,
B. T. Jannuzi,
E. LeFloc'h,
D. Stern
2006, ApJ, 648, 128
This paper applied virial black hole mass estimators to quasar
spectra from AGES (the AGN and Galaxy Evolution Survey, led
by Kochanek, Eisenstein, and the second half of the above author
list) to show that the distribution of Eddington ratios
(the ratio of the quasar luminosity to the Eddington limit for
its central black hole) is approximately log-normal with a
mean of 1/4 and a width of less than 0.3 dex, with an inequality rather
than an estimate because the observed width also includes
observational errors in the black hole mass estimates, whose
magnitude is poorly known. (Indeed, one somewhat surprising
result of this paper is to limit those observational
errors to less than 0.3 dex rms.)
This result holds for several different bins of luminosity
and redshift, with a slight trend towards lower mean ratios
at lower redshift. Crucially, for some ranges we were able
to show that it holds in bins of black hole mass, and that
the drop in the distribution towards low Eddington ratio
was not a consequence of sample selection.
The emergence of a characteristic Eddington ratio rather than
a distribution rising continuously (or staying flat) to low
values suggests that, in the quasar regime,
mass accretion rates are controlled by black-hole self-regulation
rather than by galaxy scale dynamical events.
While I am proud to be on this paper, I have to say that my
role was really as a kibbitzer, and that I deserve a tiny
fraction of credit relative to the first two authors, who
conceived the project and did nearly all of the analysis,
and relative to the authors who actually collected the data
set in the first place.
21. Feedback and recycled wind accretion: assembling the
z = 0 galaxy mass function
B. D. Oppenheimer,
R. Davé,
D. Keres,
M. Fardal,
N. Katz,
J. A. Kollmeier,
D. H. Weinberg
2010, MNRAS, 406, 2325
Our papers on cold and hot mode accretion
(Keres et al. 2005 and 2009)
used simulations that did not have an explicit recipe for driving
galactic winds, with the result that they produced overly massive galaxies
and ejected little enriched material to the circumgalactic or
intergalactic medium. This paper returned to similar topics using
the formulations of galactic winds that Oppenheimer and Davé had
developed in earlier papers focused on intergalactic metals.
The key result of this paper is that "recycling" -- the reaccretion
of material ejected in winds -- plays a major role in shaping the
mass function of galaxies, becoming the dominant mode of mass growth
for massive galaxies at low redshift. Below the characteristic mass
M*, recycling improves the agreement with the observed galaxy
mass function, but above M* it makes galaxies even more
overmassive. A plausible solution to this conundrum is AGN feedback,
not included in the simulations here.
The linked topics of accretion, winds, recycling, and the circumgalactic medium (CGM) are often referred to collectively as "the baryon cycle," and this paper played a significant role in framing this way of thinking. Our SPH collaboration has subsequently devoted a lot of effort to more detailed modeling of galactic wind launch and, more importantly, to the evolution of gas once it enters the CGM, as this will have a major impact on growth by recycling.
22. Wide-Field InfrarRed Survey Telescope-Astrophysics Focused Telescope
Assets WFIRST-AFTA 2015 Report
D. Spergel,
N. Gehrels,
C. Baltay,
D. Bennett,
J. Breckenridge,
M. Donahue,
et al.
2015, arXiv:1503.03757
The Wide Field Infrared Survey Telescope (WFIRST) is the highest priority
large space initiative recommended by the Astro2010 decadal survey,
in part thanks to input from the panel and working group reports I
helped to write.
I have served on a succession of WFIRST science definition
teams starting in 2011, and I am currently (2019) a member of the
WFIRST Formulation Science Working Group and the Cosmology with the
High Latitude Survey science investigation team (PI O. Doré).
This report presented a detailed mission concept based on a 2.5-m
telescope (AFTA) transfered to NASA by another agency; the current (2019)
mission concept remains close to the one described in this report,
but with a number of refinements and changes.
I wrote a lot of the dark energy section of this report (together with
Chris Hirata, Yun Wang, Saul Perlmutter, Charlie Baltay, and Jason Rhodes)
and contributed to other sections.
As background for Astro2020, I recently spearheaded a white paper
that briefly summarizes the current mission concept, titled
The Wide Field Infrared Survey Telescope: 100 Hubbles for the 2020s.
I am an enthusiast for WFIRST in part because of its potential for revealing the origin of cosmic acceleration, which I consider the single most important problem in contemporary cosmology, but also because it marries the revolutionary strengths of the Sloan Digital Sky Survey and the Hubble Space Telescope. If WFIRST survives the fiscal challenges ahead and makes it to launch, I hope that my contributions to its success will be a bookend to my contributions to the SDSS.
23. The Large, Oxygen-Rich Halos of Star-Forming Galaxies Are a Major
Reservoir of Galactic Metals
J. Tumlinson,
C. Thom,
J. K, Werk,
J. X. Prochaska,
T. M Tripp,
D. H. Weinberg,
et al.
2011, Science, 334, 948
The installation of the Cosmic Origins Spectrograph (COS) during
the Hubble Space Telescope 5th servicing mission opened a new opportunity
to probe the metal and gas content of galactic halos through sensitive
UV spectroscopy of background quasars. Jason Tumlinson put together
a team to carry out an ambitious systematic survey of 42 galaxies,
dubbed COS-Halos, including our SPH group as theory collaborators.
This paper presented the first major results from COS-Halos, showing
abundant OVI absorption out to distances of 150 kpc around star-forming
galaxies implying an amount of oxygen in the CGM comparable to or larger
than that in the galaxies' interstellar medium.
This paper also showed substantially less OVI in the gaseous halos
of passive galaxies, though active and passive galaxies show similar
amounts of neutral hydrogen detected in Lyman-alpha absorption.
Many simulation groups including ours
(e.g.,
Ford et al. 2016) have carried out detailed comparisons to the
COS-Halos results, and COS-Halos has itself inspired many similar
studies of different populations of galaxies.
A synthesis of the final results from COS-Halos is
presented by Werk et al. 2014.
24. Self-Consistent Models of the AGN and Black Hole Populations: Duty Cycles, Accretion Rates, and the Mean Radiative Efficiency
F. Shankar,
D. H. Weinberg,
J. Miralda-Escudé
2009, ApJ, 690, 20
One of the most elegant results in the study of AGN is the argument due to
Soltan
and Paczynski that links the integrated emissivity of the quasar population
to the mean present-day mass density of relic black holes. In this paper
we extended this technique to predict the full shape of the relic black
hole mass function based on the full shape and redshift evolution of the
quasar luminosity function. This calculation constrains the mean
radiative efficiency of quasar accretion and the Eddington ratios and
duty cycles of the accreting black holes. I think this paper has been
influential in part because we explained these connections clearly and
in part because Francesco Shankar devoted enormous effort to
compiling and comparing the relevant observational results.
Observational uncertainties remain a challenge in this line of investigation,
and Francesco remains a leader in reconciling a multitude of results
into a physically coherent picture. My own involvement in this field
traces back to my
2001 paper with Paul Martini on quasar clustering and its connection
to quasar lifetimes.
25. On the Mass-to-Light Ratio of Large-Scale Structure
J. L. Tinker,
D. H. Weinberg,
Z. Zheng,
I. Zehavi
2005, ApJ, 631, 41
This paper, a chapter of Jeremy Tinker's PhD thesis,
was our first attempt to derive cosmological parameter constraints
from HOD modeling.
We showed that if we fit the observed SDSS galaxy correlation function
(Zehavi et al. 2005) in a cosmological model with
the then-standard parameter values Omegam=0.3 and
sigma8=0.9, we predicted mass-to-light ratios of
clusters higher than observed. From a joint fit we inferred
(sigma8/0.9)(Omegam/0.3)0.6 = 0.75 +/- 0.06,
perfectly anticipating the change in preferred parameter values
that came with the transition from the 1st-year WMAP CMB data to
the 3rd-year data (mainly because WMAP1 had overestimated the
electron scattering optical depth as a result of underestimated polarization
foregrounds). Along with papers making closely related arguments by
Vale & Ostriker
and
van den Bosch,
Mo, & Yang,
this paper was one of the early cosmological successes of
halo-based approaches to galaxy clustering.
We revisited this method with many improvements in the data and the modeling
in
Tinker et al. 2011.
26. Cosmological implications of baryon acoustic oscillation measurements
E. Aubourg,
S. Bailey,
J. E. Bautista,
F. Beutler,
V. Bhardwaj,
D. Bizyaev,
et al.
2015, Phys Rev D, 92, 13516
This paper synthesized baryon acoustic oscillation (BAO) measurements
from the SDSS-III Baryon Oscillation
Spectroscopic Survey (BOSS) into constraints on a wide range of
cosmological models, in combination with cosmic microwave background
(CMB) and Type Ia supernova (SN) data. I particularly liked the
approach in this paper, devised largely by Anze Slosar, for combining
BAO measurements with a 3-parameter data vector summarizing the CMB
constraints most relevant to cosmic geometry, which allowed us to
give intuitive explanations rather than "black box" results.
Among our key results: using only the sound horizon calibration from the CMB,
BAO and SN data combine to give a tight "inverse distance ladder"
constraint of H0 = 67.3 +/- 1.1 km/s/Mpc even with very
flexible dark energy models;
a curvature constraint Omegak = -0.003 +/- 0.003
assuming constant dark energy; a constraint w = -0.97 +/- 0.05 for
a flat wCDM cosmology; a 0.5 eV upper limit on neutrino mass from
expansion history alone; tension at the 2-2.5 sigma level between
the BOSS Lya forest BAO measurements and any dark energy model that
fits the CMB and galaxy BAO data; and tension between dark energy
models constrained by the expansion history data and many measurements
of matter clustering at low redshift.
This paper represents the collective efforts of a large and talented
collaboration; Slosar and I did a lot of the wrangling and writing.
The analysis of the final BOSS galaxy clustering measurements by
Alam et al. 2017, which includes constraints from the broad band
power spectrum and redshift space distortion as well as BAO,
supersedes this paper in terms of cosmological constraints, but
the intuitive explanations make Aubourg et al. my personal favorite
among the BOSS cosmology papers.
27. Percolation Galaxy Groups and Clusters in the SDSS Redshift Survey:
Identification, Catalogs, and the Multiplicity Function
A. A. Berlind,
J. A. Frieman,
D. H. Weinberg,
M. R. Blanton,
M. S. Warren,
K. Abazajian,
et al.
2006, ApJ Supp, 167, 1
In Berlind & Weinberg (2002) we concluded
that the multiplicity function of galaxy groups would be a powerful
tool for constraining the HOD and breaking degeneracies between
galaxy bias and cosmology. As a postdoc at Chicago, Andreas Berlind
set forth to construct a group catalog from the SDSS and measure
the multiplicity function. This paper presents Andreas's
group catalog and careful investigation of contamination and incompleteness
biases with matched analysis of simulations; the group catalog has
been used by many investigators over many years for many purposes.
A lovely recent paper by
Sinha, Berlind,
et al. (I am an appreciative reader but not a co-author)
finally realizes the vision of constraining the HOD
jointly with the multiplicity function and projected correlation function,
and it shows why doing this properly was much harder than we thought it would
be in 2002 ...
28. The Halo Occupation Distribution and the Physics of Galaxy Formation
A. A. Berlind,
D. H. Weinberg,
A. J. Benson,
C. M. Baugh,
S. Cole,
R. Davé,
C. S. Frenk,
A. Jenkins,
N. Katz,
C. G. Lacey
2003, ApJ, 593, 1
This paper,
based on Andreas Berlind's thesis research,
investigated physical predictions for the halo occupation
distribution from SPH simulations and from semi-analytic
models of galaxy formation. The first key finding was that
the HODs predicted by the two methods agreed remarkably well
once we corrected for the fact that they predicted different
galaxy stellar mass functions. Other key findings were the
form of the HOD: a sharp rise from zero to one over a narrow
range of halo mass, a slowly rising plateau from one to two
over a factor of ~20 in halo mass, and a roughly linear
relation between halo mass and galaxy number at high masses.
Fluctuations about the mean are sub-Poisson at low masses,
which has a crucial impact on clustering statistics, and
the HOD depends strongly on the age of the stellar population,
with older galaxies preferentially residing in high mass halos.
We connected these trends to the physics in the galaxy
formation models.
Zheng et al. 2005 was the successor
to this paper.
29. On Departures from a Power Law in the Galaxy Correlation Function
I. Zehavi,
D. H. Weinberg,
Z. Zheng,
A. A. Berlind,
J. A. Frieman,
R. Scoccimarro,
et al.
2004, ApJ, 608, 16
One of the conclusions of Berlind & Weinberg 2002
was that it is relatively hard to get a power-law galaxy correlation function,
and that the combination of cold dark matter cosmology and HOD
models generically predicts an inflection in the correlation
function at scales of ~ 1-2 Mpc, the transition from dominance
by galaxy pairs in a single halo to galaxy pairs in separate halos.
At the simplest level, the physics behind this inflection is that
galaxies orbit within halos, so this scale marks a transition
from "single stream" cosmological flows to a "multi-stream" regime
where galaxies can encounter other galaxies that have changed
direction.
As the SDSS redshift survey grew beyond the early sample analyzed in
Zehavi et al. 2002, the increased measurement precision
gave us a chance to test this prediction. We showed that there
is a statistically significant departure from a power-law correlation
function for SDSS galaxies that is naturally explained in the
HOD framework. This paper also required developing the HOD
modeling calculations themselves to the level of accuracy demanded
by the precise measurements. These deviations from a power-law
were confirmed and examined as a function of galaxy properties
in Zehavi et al. 2005.
30. The COS-Halos Survey: Physical Conditions and Baryonic Mass in
the Low-redshift Circumgalactic Medium
J. K. Werk,
J. X. Prochaska,
J. Tumlinson,
M. Peeples,
T. M. Tripp,
A. J. Fox,
et al.
2014, ApJ, 792, 8
This paper presents the synthesis interpretation of results from
COS-Halos, using the Hubble Space Telescope and ground-based
(Keck Telescope) absorption line measurements of multiple ionization
states of multiple elements to constrain CGM properties galaxy by galaxy,
using equilibrium CLOUDY models fit to the data.
The results demonstrate that typical galaxies in
COS-Halos have massive amounts of cool gas in the CGM, at least
2e10 Msun and probably half or more of the baryon content expected
for the halo mass. They also show that this cool gas is relatively
low density, far lower than would be required for pressure equilibrium
with a virial temperature hot gas halo.
There are some unavoidable uncertainties in the modeling assumptions,
but this paper presents striking evidence for a massive cool CGM,
which is not easy to explain in simple models of galaxy formation.
31. Cold dark matter: Controversies on small scales
D. H. Weinberg,
J. S. Bullock,
F. Governato,
R. Kuzio de Naray,
A. H. G. Peter
2015, Proc Natl Acad Sci, 112, 12249
In 2013 I organized a panel for the National Academies'
Sackler Symposium on Dark Matter, with a focus on the
challenges to the cold dark matter (CDM) model from small
scale observations -- the inner rotation curves and satellite
populations of the Milky Way and other disk galaxies.
The resolution to these challenges could lie in new dark matter
physics, such as self interactions, or it could lie in baryonic
physics effects that redistribute cold dark matter on kpc scales.
This short review article summarizes our panel discussion.
I think it has been particularly useful in encapsulating the
observational situation for physicists whose expertise is in
dark matter phenomenology rather than galaxy properties.
32. Hierarchical Galaxy Formation and Substructure in the Galaxy's Stellar Halo
J. S. Bullock,
A. V. Kravtsov,
D. H. Weinberg
2001, ApJ, 548, 33
For the dwarf satellite study in Bullock,
Kravtsov, & Weinberg 2000,
James and Andrey developed a semi-analytic model to track
the mergers and orbits of subhalos into a Milky Way mass parent
halo, populate them with stars, and decide which ones survived.
When early papers from the SDSS showed evidence of multiple
large substructures in the Galactic halo
(e.g.,
Ivezic et al. 2000,
Yanny, Newberg, et al. 2000,
we decided we should check whether the disrupted
satellites in this model could produce the kinds of structures
turning up in the SDSS and other halo surveys. To our great
surprise, we found that the disrupted satellites in this model
could produce not just structure in the halo but the entire
stellar halo itself, including its total mass and average
radial profile. This idea is similar to that proposed by
Searle & Zinn 1978, based on empirical arguments, but here
it is shown to be a natural consequence of galaxy formation
theory in the cold dark matter scenario. We presented simple
visualizations and statistics that could be used to test
the hypothesis, showing, in particular, that substructure would
remain more evident in the outer halo because of the smaller
number of contributing systems and the longer mixing times.
James Bullock, Kathryn Johnston, and their collaborators have
since extended this model into a much more sophisticated and
powerful framework for predicting properties of the stellar halo
(e.g.,
Bullock & Johnston 2005,
Johnston et al. 2008),
and the first statistical tests against substructure observed
in the SDSS look encouraging
(Bell
et al. 2008,
Xue et al. 2010).
33. Quasar Clustering and the Lifetime of Quasars
P. Martini,
D. H. Weinberg
2001, ApJ, 547, 12
This paper proposed a novel method to constrain the lifetime of
high redshift quasars: since the number density of quasars is observed,
if they are long-lived then their host dark matter halos must be rare
and should be strongly clustered, while if they are short-lived then their
host dark matter halos are common and they should be less clustered.
Quasar clustering measurements at the time were too uncertain to
derive much of a constraint, but the concepts developed here have
played a big part in interpreting subsequent clustering measurements
from the SDSS and other quasar surveys. If we were writing the paper
now we would probably frame the discussion in terms of
duty cycles (like Shankar et al. 2009) instead
of lifetimes. I no longer clearly remember, but I think this paper
must also have had a significant effect on my early thinking about HODs,
which took root in the thesis of Martini's graduate school classmate
Andreas Berlind.
34. Wide-Field InfraRed Survey Telescope-Astrophysics Focused Telescope Assets
WFIRST-AFTA Final Report
D. Spergel,
N. Gehrels,
J. Breckinridge,
M. Donahue,
A. Dressler,
B. S. Gaudi,
et al.
2013, arXiv:1305.5422
This report is the predecessor to the 2015
report cited above. I spearheaded a summary version of this
report, titled
WFIRST-2.4: What Every Astronomer Should Know.
35. Galaxies and gas in a cold dark matter universe
N. Katz,
L. Hernquist,
D. H. Weinberg
1992, ApJ, 399, L109
This is the first paper from our SPH collaboraton, and the first
paper to show that incorporating gas dynamics and radiative cooling
in a simulation of a cosmological volume led to the formation
of dense clumps of cold gas with the approximate masses and sizes
of the stellar components of galaxies, and to the formation of
groups containing multiple galaxies in a common dark matter halo.
While this behavior was anticipated by analytic models
of galaxy formation, it was reassuring to see it work out in
a full calculation. This paper also presented first calculations
of galaxy clustering and galaxy bias from hydrodynamic cosmological
simulations, albeit in a very small box.
36. Protecting Life in the Milky Way: Metals Keep the GRBs Away
K. Z. Stanek,
O. Y. Gnedin,
J. F. Beacom,
A. P. Gould.,
J. A. Johnson,
J. A. Kollmeier,
M. Modjaz,
M. H. Pinsonneault,
R. Pogge,
D. H. Weinberg
2006, Acta Astronomica, 56, 333
This paper emerged from a discussion at
OSU Astro Coffee
in which Kris Stanek remarked that all of the long GRBs identified
with supernovae in nearby galaxies were in low metallicity systems.
Under the tutelage of Andy Gould, OSU astronomers have long been
aficionados of small number statistics, and from this discussion
we convinced ourselves that GRBs must arise preferentially in
low metallicity stars rather than tracing star formation.
I did almost none of the work needed to convert this lively conversation
into a paper, but I guess I deserve some credit for the fact that
we were having the coffee conversation in the first place.
We were given grief by our first referee for drawing strong conclusions
from a sample of five, but I think this conclusion has held up
pretty well. Doom and gloom papers about GRBs destroying life on earth were
popular at the time, hence the planetary safety focus of the title.
37. Cooling Radiation and the Lyα Luminosity of Forming Galaxies
M. A. Fardal,
N. Katz,
J. P. Gardner,
L. Hernquist,
D. H. Weinberg,
R. Davé
2001, ApJ, 562, 605
The motivation for this paper was the discovery of giant Lyman-alpha
emission nebulae ("Lyman-alpha blobs") by
Steidel et al. 2000, which did not have evident central AGN
to power them by photoionization.
We investigated our simulations to see if these objects could be
powered by cooling radiation onto forming galaxies.
Our answer was a tentative "yes", at least as far as energetics went.
In retrospect, the most important implication of this paper was
off to the side of its main topic: because so much of the gravitational
potential energy was being radiated in Lyman-alpha, it meant that
most of the gas cooling onto galaxies was never heated to the halo
virial temperature. This realization led us to undertake a more
thorough investigation establishing the primacy of cold mode accretion,
in the
Katz et al. 2003 conference proceeding and the
Keres et al. 2005 journal article.
The conventional wisdom now seems to be that giant Lyman-alpha nebulae
are mostly powered by AGN (sometimes obscured), but gravitational
cooling radiation may still play a role.
38. Photoionization Feedback in Low-Mass Galaxies at High Redshift
M. Dijktstra,
Z. Haiman,
M. J. Rees,
D. H. Weinberg
2004, ApJ, 601, 666
This paper is a partial counter-point to
Thoul & Weinberg 1996.
Dijkstra and Haiman adapted Thoul's 1-d hydro code to model
the collapse and cooling of gas in low mass halos at high redshift,
near the epoch of reionization, and they found that because of high
densities, self-shielding, and a low ionizing background intensity,
the suppression of low mass galaxy formation is much weaker in these
conditions, allowing galaxies to form in halos with circular velocities
down to 10 km/s. This substantially increases the population of low
mass galaxies that can contribute to reionization. My direct contribution
to this paper was quite small, but I'm pleased to be part of it because
it is, surprisingly, my only paper with any of these three co-authors.
39. Chemical Cartography with APOGEE: Metallicity Distribution Functions and the Chemical Structure of the Milky Way Disk
M. R. Hayden,
J. Bovy,
J. A. Holtzman,
D. L. Nidever,
J. C. Bird,
D. H. Weinberg,
et al.
The SDSS-III APOGEE survey drew me into
the field of Galactic chemical evolution. This is my favorite of all
of the APOGEE-1 papers, mapping the distribution of stars in [alpha/Fe]
vs. [Fe/H] (the second measuring overall metal content, the first measuring
the ratio of core collapse supernova elements relative to total enrichment)
as a function of position in the Galactic disk. At most locations, there
are two distinct tracks in this space. The relative number of stars on
the two tracks, and the [Fe/H] distribution of those stars, varies strongly
with Galactocentric radius and vertical distance from the disk midplane.
The shape of the [Fe/H] distribution changes with radius, a likely signature
of radial migration of stars. For the first time, APOGEE was able to
map these distributions across the disk with large enough numbers of stars
to provide excellent statistics. My students and I contributed theoretical
interpretation to go along with these beautiful observational findings.
We have recently (
Weinberg et al. 2019)
used APOGEE-2 data to map a much larger set of abundance ratios across
the disk, with further striking results.
40. The Power Spectrum of Mass Fluctuations Measured from the Lyα Forest at Redshift z = 2.5
R. A. C. Croft,
D. H. Weinberg,
M. Pettini,
L. Hernquist,
N. Katz
1999, ApJ, 520, 1
After the Croft et al. 1998 paper on power spectrum
recovery from the Lyman-alpha forest, we collaborated with Max Pettini
to apply the method to an observational data set, a sample of 19
quasar spectra originally collected to study damped Lyman-alpha systems.
We significantly improved our understanding of the method itself and
how to characterize what we could learn from observations, so although
this paper was superseded by
Croft et al. 2002, which analyzed a larger sample,
it played an important role in the development of our Lyman-alpha
forest cosmology program.