The Ohio State University College of Mathematical & Physical Sciences Department of Astronomy

Galaxy Images

NGC 4038/4039 (The "Antennae" Colliding Galaxies)

``True-color'' image of the Antennae, a pair of galaxies colliding with one another. This image is composed of separate B, R, and H-band filter images combined as blue, green, and red colors. Blue shows regions of recent star formation triggered by the collision, red shows dusty regions, and yellow where the light is dominated primarily by the older stars that made up the original galaxies. Most of the star formation is in bright knots (actually immense clusters of hot, young stars), a few of which can be glimpsed through the dust as the reddish knots in the main body of the colliding galaxies.

(62Kb GIF)

This two-panel image shows the separate B- and H-band images that made up the Blue and Red images in the color image above. They demonstrate the profound differences in the appearance of this pair of colliding galaxies when viewed in blue-light (left) and infrared-light (right), primarily reflecting the greatly decreased importance of obscuration due to dust at infrared wavelengths, as well as differences in the populations of the stars responsible for emitting most of the light at those wavelengths.

Tek 1024x1024 CCD, and NICMOS-3 IR Array, 1.5-meter Telescope, Cerro Tololo Interamerican Observatory, Chile.

[Composition: Pogge; Observers: Sellgren & Tiede; Reduction: Quillen & Tiede]
(OSU Bright Spiral Galaxy Survey)

NGC 2207/IC 2163 (Interacting Galaxies)

``True-color'' image of a pair of interacting galaxies, the smaller clearly behind the larger (notice the dust lanes crossing in front of the smaller galaxy, IC 2163, that are extensions of the blue spiral arms in the larger galaxy, NGC 2207). This image is composed of separate B, R, and H-band filter images combined as blue, green, and red colors.

Tek 1024x1024 CCD, and NICMOS-3 IR Array, 1.5-meter Telescope, Cerro Tololo Interamerican Observatory, Chile.

[Composition: Pogge & Frogel; Observers: Sellgren & Tiede; Reduction: Quillen & Tiede]
(OSU Bright Spiral Galaxy Survey)

NGC 2442 (Bright Spiral Galaxy)

``True-color'' image of a bright spiral galaxy, chosen to emphasize star formation regions and the dust lanes. This image is composed of separate B, R, and H-band filter images combined as blue, green, and red colors.

(96Kb GIF)

This two-panel image shows the separate B- and H-band images that made up the Blue and Red images in the color image above, demonstrating that in even normal galaxies there can be profound differences in appearance when viewed in blue-light (left) versus infrared-light (right). As in NGC 4038/39 above, the differences primarily reflect the substantially smaller effects of dust obscuration at infrared wavelengths, as well as differences in the populations of the stars responsible for emitting most of the light at the respective wavelengths.

Tek 1024x1024 CCD, and NICMOS-3 IR Array, 1.5-meter Telescope, Cerro Tololo Interamerican Observatory, Chile.

[Composition: Pogge & Frogel; Observers: Sellgren & Tiede; Reduction: Quillen & Tiede]
(OSU Bright Spiral Galaxy Survey)

A Collection of OSU Galaxy Survey Color Images

All observations were made at various telescopes (see notes) by the OSU Bright Galaxy Survey team, and reduced and composed by team members, and especially by new team member Roelf deJong at the University of Durham, who wrote the scaling and color combination scripts used for most of the images below.

24-bit TIF images of some of these image are available upon written request.

NGC 613

NGC 625

NGC 1350

NGC 1511

NGC 5054

NGC 5161

Optical Images were obtained with a Tek 1024x1024 CCD, and IR images with a NICMOS-3 IR Array, both using the 1.5-meter Telescope of the Cerro Tololo Interamerican Observatory, Chile.

[Composition: Jay Frogel]
(OSU Bright Spiral Galaxy Survey)

NGC 1068 (Seyfert 2 Galaxy)

``True-color'' stellar continuum image of the Seyfert 2 Galaxy NGC 1068 (Messier 77), composed of UV, green, and red narrowband filters chosen to reject bright emission lines and only admit starlight.

Prime Focus Camera + Loral 512x512 CCD, 3.6-meter Canada-France-Hawaii Telescope, Mauna Kea, Hawaii

[Observers: Pogge & De Robertis; Reduction & Composition: Pogge]

NGC 7714/15 (Interacting Galaxies)

Narrowband (5nm) H-alpha+[N II] Emission and Stellar Continuum Images of the interacting galaxy pair NGC 7714/7715.

The upper panel shows just the starlight in these two galaxies, while the bottom shows the hot gas ionized by very hot, massive young stars. In the lower panel, the the starlight has been subtracted away using the stellar continuum image to show just the ionized gas regions.

NGC 7714 is a famous "starburst" galaxy, notice the very bright emission-line regions inthe nucleus and surrounding regions. Notice also that its partner, NGC 7715, is essentially devoid of starformation, so on the starlight-subtracted image (lower), it vanishes entirely. The faint gray "fog" in the lower left-hand corner of the top panel is scattered light from a very bright foreground star just off the field.

OSU Imaging Fabry-Perot Spectrograph + TI 800x800 CCD, 1.8-meter Perkins Telescope, Anderson Mesa, AZ

[Credit: Pogge]

NGC 4138 (Star-forming S0 Galaxy)

Imaging Fabry-Perot Spectrograph + TI 800x800 CCD, 1.8-meter Perkins Telescope, Anderson Mesa, AZ

[Observers: Pogge & Eskridge; Reduction & Composition: Pogge]

NGC 5850 (Barred Galaxy)

Sum of BVR broad-band images of NGC 5850 (Field of View: 6.8 arcminutes)

Tek 1024x1024 CCD, 0.9-meter Telescope, Cerro Tololo Interamerican Observatory, Chile.

[Observer: Roberto Aviles; Reduction & Composition: Pogge]
(OSU Bright Spiral Galaxy Survey)

NGC 3351 (Nuclear Ring Galaxy)

V-band image of NGC 3351 (Field of View: 6.8 arcminutes)

Tek 1024x1024 CCD, 0.9-meter Telescope, Cerro Tololo Interamerican Observatory, Chile

[Observer: Roberto Aviles; Reduction: Quillen & Pogge; Composition: Pogge]
(OSU Bright Spiral Galaxy Survey)

(57Kb GIF)

H-alpha emission-line Flux and H-alpha velocity map of a nuclear HII-region ring in the central 30-arcseconds of NGC 3351.

The left-hand panel shows H-alpha emission-line flux from gas ionized by a ring of hot massive young stars in the center of the galaxy. Flux is coded in a "rainbow" pseudo-color map.

The right-hand planel shows a map of the line-of-sight velocities of the ionized gas measured using an Imaging Fabry-Perot Spectrometer. Velocties are coded as Blue=approaching, Red=receding, with a full range of +/-150 km/sec.

OSU Imaging Fabry-Perot Spectrograph + TI 800x800 CCD, 1.8-meter Perkins Telescope, Anderson Mesa, AZ

[Credit: Pogge]

NGC 1097 (Barred Galaxy)

IR and Visible Images of the barred galaxy NGC 1097 (Field of View: 5 arcminutes)

Left: B-band image with a Tek 1024x1024 CCD
Right: J-band image with OSIRIS

0.9-meter and 1.5-meter Telescopes, Cerro Tololo Interamerican Observatory, Chile.

[Observers: Quillen & Frogel; Reduction & Composition: Quillen]