galaxy / star spectra
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by
Budgieye
moderator
Is the galaxy spectrum contaminated by a foreground star?
The disk is a red star.
Red stars tend to have many absorption troughs in their spectra, because they are "cool" and the gases around it can absorb light.
The emission peaks of the galaxy behind will be at values of z=0.14
The absorption troughs (the opposite of peaks) of the star will be z=0
http://www.gama-survey.org/dr2/data/spectra/gama/reduced_08/1d/png/G15_Y1_DN2_125.png
So, find a typical red star for comparison.
typical red star
Typical red star spectrum
http://skyserver.sdss.org/dr9/en/tools/explore/obj.asp?id=1237667430106661549There are some unlabelled troughs in the galaxy spectrum.
I can't match them as absorbed by the red star, but maybe I don't know enough.
Any ideas anyone?
Posted
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by
Budgieye
moderator
note: yellow stars are green in SDSS
yellow stars are green in SDSS
http://skyserver.sdss.org/dr9/en/tools/explore/obj.asp?id=1237654881262239849
The main height is at 6000, so it is a yellow star.
Reading
Spectra guide for SDSS images in Galaxy Zoo Talk https://talk.galaxyzoo.org/#/boards/BGZ0000001/discussions/DGZ0000ulp?page=3&comment_id=53fef2ee3d5a77490c0001b6
Posted
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YES, this is good thank you. Haven’t found a good match yet but will keep on searching.
In the meantime, I believe the 3.2 Spectra Guide example star ‘red giant star’ links to an early type M Dwarf (M0 or M1).
EDIT: SDSS colour seems to match early M Dwarfs pretty well, dark orangy.
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SDSS gri, VSTKIDS gri and VIKING JHK images.
Seems like a star. Oddly no apparent galaxy nucleus at all (?), but bright in WISE W1 + W2.
http://cutout.icrar.org/tmp/15154533175177/index_temp.php
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