Andrew Yee
October 18th 05, 03:35 PM
Subaru Telescope
National Astronomical Observatory of Japan
Hilo, Hawaii
October 13, 2005
A Galactic Space Halo -- NGC2403
Subaru Telescope, using Suprime-Cam, took the clearest most complete image
to date of the spiral galaxy NGC 2403. At a distance of 10 million light
years, NGC 2403 is an Sc type galaxy, which has open spiral arms and a
small nucleus. It is approximately half the mass of our own galaxy, the
Milky Way, and has an abundance of neutral hydrogen gas. In the spiral
arms we see active star formation regions in red, clusters of young blue
stars called OB associations, and darker regions called dust lanes where
light is blocked by gas and dust within the galaxy.
This is not the first time NGC 2403 has been studied. Edwin Hubble used
NGC 2403 as evidence that more distant galaxies move more quickly away
from us, now called Hubble's Law. It was also used to develop the
Tully-Fisher relation, which states that there is a relation between a
galaxy's rotational speed and its brightness. NGC 2403 has become an
important standard galaxy when deciding the distances to other galaxies,
as we recognize the vast expanse of space.
Larger galaxies are thought to have developed from the collision and
merger of smaller galaxies. Mergers can leave enduring marks on a galaxy's
halo, the most extended and generally spherical component of a galaxy.
There is evidence that relatively young stars exist in the halo of NGC
2403, hinting at a recent merger with another galaxy. Astronomers are now
studying this image to see if the color and brightness of the stars in the
halo of NGC 2403 will reveal conclusive evidence of past mergers.
Object Name: Spiral Galaxy (NGC2403)
Telescope: Subaru Telescope / Prime Focus
Instrument: Suprime-Cam
Filter: B (0.45 micron) , R (0.65 micron) , IA651 (0.651 micron)
Color: Blue (B), Green (R) , Red (IA651)
Date: UT2002 Oct. 31 (B), Nov. 5 (R), Oct. 30 (IA651)
Exposure: 960 sec. (B), 480 sec. (R), 480 sec. (IA651)
Field of View: 26.7 x 21.3 arcmins
Orientation: North up, east left
Position: RA(J2000.0) = 7h37m, Dec(J2000.0) = +65d36m (Camelopardalis)
IMAGE:
* Small size (205 KB)
http://www.subaru.naoj.org/Pressrelease/2005/10/13/image_84.jpg
* Medium Size(680 KB)
http://www.subaru.naoj.org/Pressrelease/2005/10/13/image_220.jpg
* Large size (2.2 MB)
http://www.subaru.naoj.org/Pressrelease/2005/10/13/image_450.jpg
National Astronomical Observatory of Japan
Hilo, Hawaii
October 13, 2005
A Galactic Space Halo -- NGC2403
Subaru Telescope, using Suprime-Cam, took the clearest most complete image
to date of the spiral galaxy NGC 2403. At a distance of 10 million light
years, NGC 2403 is an Sc type galaxy, which has open spiral arms and a
small nucleus. It is approximately half the mass of our own galaxy, the
Milky Way, and has an abundance of neutral hydrogen gas. In the spiral
arms we see active star formation regions in red, clusters of young blue
stars called OB associations, and darker regions called dust lanes where
light is blocked by gas and dust within the galaxy.
This is not the first time NGC 2403 has been studied. Edwin Hubble used
NGC 2403 as evidence that more distant galaxies move more quickly away
from us, now called Hubble's Law. It was also used to develop the
Tully-Fisher relation, which states that there is a relation between a
galaxy's rotational speed and its brightness. NGC 2403 has become an
important standard galaxy when deciding the distances to other galaxies,
as we recognize the vast expanse of space.
Larger galaxies are thought to have developed from the collision and
merger of smaller galaxies. Mergers can leave enduring marks on a galaxy's
halo, the most extended and generally spherical component of a galaxy.
There is evidence that relatively young stars exist in the halo of NGC
2403, hinting at a recent merger with another galaxy. Astronomers are now
studying this image to see if the color and brightness of the stars in the
halo of NGC 2403 will reveal conclusive evidence of past mergers.
Object Name: Spiral Galaxy (NGC2403)
Telescope: Subaru Telescope / Prime Focus
Instrument: Suprime-Cam
Filter: B (0.45 micron) , R (0.65 micron) , IA651 (0.651 micron)
Color: Blue (B), Green (R) , Red (IA651)
Date: UT2002 Oct. 31 (B), Nov. 5 (R), Oct. 30 (IA651)
Exposure: 960 sec. (B), 480 sec. (R), 480 sec. (IA651)
Field of View: 26.7 x 21.3 arcmins
Orientation: North up, east left
Position: RA(J2000.0) = 7h37m, Dec(J2000.0) = +65d36m (Camelopardalis)
IMAGE:
* Small size (205 KB)
http://www.subaru.naoj.org/Pressrelease/2005/10/13/image_84.jpg
* Medium Size(680 KB)
http://www.subaru.naoj.org/Pressrelease/2005/10/13/image_220.jpg
* Large size (2.2 MB)
http://www.subaru.naoj.org/Pressrelease/2005/10/13/image_450.jpg