J/MNRAS/444/2456 Spectral galaxy pairs from SDSS DR9 (Yang+, 2014)
A search for spectral galaxy pairs of overlapping galaxies based on fuzzy
recognition.
Yang H., Luo A., Chen X., Zhang J., Hou W., Cai J., Wei P., Ren J., Liu X.,
Zhao Y.
<Mon. Not. R. Astron. Soc., 444, 2456-2469 (2014)>
=2014MNRAS.444.2456Y 2014MNRAS.444.2456Y
ADC_Keywords: Galaxy catalogs ; Redshifts ; Morphology
Keywords: methods: data analysis - dust, extinction - galaxies: evolution -
galaxies: ISM
Abstract:
Spectral galaxy pairs (hereafter as SGPs) are composite galaxy spectra
that contain two independent redshift systems. These spectra are
useful for studying the dust properties of the foreground galaxies. In
this article, a total of 165 spectra of SGPs are mined from the Sloan
Digital Sky Survey (SDSS) Data Release 9 (DR9) using the concept of
'membership degree' from fuzzy set theory, especially defined to be
suitable for fuzzy identification of emission lines. The spectra and
images of this sample are classified according to their membership
degree and image features, respectively. Many of the second redshift
systems are too small or too dim to select from SDSS images alone,
making the sample a potentially unique source of information on dust
effects in low-luminosity or low surface brightness galaxies, which
are underrepresented in morphological pair samples. The dust
extinction of those objects with high membership degree is also
estimated by Balmer decrement. Additionally, analyses for a series of
spectroscopic observations of one SGP from 165 systems indicate that a
newly star-forming region of our Milky Way might exist.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 91 165 SGP (Spectral Galaxy Paris) sample
selected from SDSS DR9
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See also:
http://www.sdss.org : SDSS Home Page
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 3 I3 --- Seq [1/165] SGP sequential number
4 A1 --- n_Seq [*] 2 redshift values exist in SDSS (1)
6- 9 A4 --- --- [SDSS]
11- 29 A19 --- SDSS SDSS source name (2)
31- 39 F9.5 deg RAdeg ?=- Right ascension (J2000)
41- 49 F9.5 deg DEdeg ?=- Declination (J2000)
51- 56 F6.4 --- z1 [0/0.22] First redshift (3)
58- 64 F7.5 --- e_z1 [0/0.02] rms uncertainty on z1 (3)
66- 71 F6.4 --- z2 [0/0.38] Second redshift (3)
73- 79 F7.5 --- e_z2 [0/0.10] rms uncertainty on z2 (3)
81 A1 --- Grade [ABCD] Grade level of spectrum, A=best (4)
83- 85 A3 --- Env Environment of the SGP (5)
87- 91 A5 --- Refs Relevant references for objects that appear
in the literature (6)
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Note (1): * indicates sources for which there are at least two values in the
XCRedshift results close to the values identified by our method.
Note (2): SDSS JHHMMSS.ss+DDMMSS.s, except source 130, Plate-MJD-Fiber.
Note (3): The two redshifts (errors) are determined from the core wavelength of
the best-fitting emission lines.
Note (4): Level is classified according to different membership degree
thresholds.
Note (5): Environment is classified from visual inspection as follows:
FPV = Face-on-Pair Visible. Two galaxies can be separated visually in the
image and they are both face-on to us.
FPI = Face-on-Pair Invisible
FGV = Face-on-Group Visible. These are multiple galaxy systems. Most of the
galaxies in these systems are face-on to us and several objects can be
separated in the images.
FGI = Face-on-Group Invisible
EPV = Edge-on-Pair Visible. The main difference with FPV is that these
galaxies are edge-on to us.
EPI = Edge-on-Pair Invisible.
EGI = Edge-on-Group Invisible.
Note (6): Notes as follows:
1 = Eke et al. (2004MNRAS.348..866E 2004MNRAS.348..866E, Cat. J/MNRAS/348/866)
2 = Merchan & Zandivarez (2005)
3 = Berlind et al. (2006ApJS..167....1B 2006ApJS..167....1B, Cat. J/ApJS/167/1)
4 = Allam et al. (2004AJ....127.1883A 2004AJ....127.1883A, Cat. J/AJ/127/1883)
5 = Keel et al. (2013PASP..125....2K 2013PASP..125....2K, Cat. J/PASP/125/2)
6 = Holwerda, Keel & Bolton (2007AJ....134.2385H 2007AJ....134.2385H, Cat. J/AJ/134/2385)
7 = Liu et al. (2011ApJ...737..101L 2011ApJ...737..101L, Cat. J/ApJ/737/101)
8 = Ge et al. (2012ApJS..201...31G 2012ApJS..201...31G, Cat. J/ApJS/201/31)
9 = McConnachie et al. (2009MNRAS.395..255M 2009MNRAS.395..255M, Cat. J/MNRAS/395/255)
10 = Kopparapu et al. (2008ApJ...675.1459K 2008ApJ...675.1459K, Cat. J/ApJ/675/1459)
11 = Marino et al. (2013MNRAS.428..476M 2013MNRAS.428..476M)
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History:
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(End) Patricia Vannier [CDS] 28-Apr-2015