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J/ApJ/733/74     GALEX - SDSS properties of local galaxies     (Lemonias+, 2011)

The space density of extended ultraviolet (XUV) disks in the local universe and implications for gas accretion onto galaxies. Lemonias J.J., Schiminovich D., Thilker D., Wyder T.K., Martin D.C., Seibert M., Treyer M.A., Bianchi L., Heckman T.M., Madore B.F., Rich R.M. <Astrophys. J., 733, 74 (2011)> =2011ApJ...733...74L
ADC_Keywords: Galaxies, nearby ; Photometry, SDSS ; Photometry, ultraviolet Keywords: galaxies: evolution - galaxies: formation - galaxies: structure - surveys - ultraviolet: galaxies Abstract: We present results of the first unbiased search for extended ultraviolet (XUV)-disk galaxies undertaken to determine the space density of such galaxies. Our sample contains 561 local (0.001<z<0.05) galaxies that lie in the intersection of available Galaxy Evolution Explorer (GALEX) deep imaging (exposure time >1.5x104s) and Sloan Digital Sky Survey DR7 footprints. We explore modifications to the standard classification scheme for our sample that includes both disk- and bulge-dominated galaxies. Visual classification of each galaxy in the sample reveals an XUV-disk frequency of up to 20% for the most nearby portion of our sample. On average over the entire sample (out to z=0.05) the frequency ranges from a hard limit of 4%-14%. The GALEX imaging allows us to detect XUV disks beyond 100 Mpc. The XUV regions around XUV-disk galaxies are consistently bluer than the main bodies. We find a surprisingly high frequency of XUV emission around luminous red (NUV-r>5) and green valley (3<NUV-r<5) galaxies. The XUV-disk space density in the local universe is >(1.5-4.2)x10-3Mpc-3. Using the XUV emission as an indicator of recent gas accretion, we estimate that the cold gas accretion rate onto these galaxies is >(1.7-4.6)x10-3M/Mpc3/yr. The number of XUV disks in the green valley and the estimated accretion rate onto such galaxies points to the intriguing possibility that 7%-18% of galaxies in this population are transitioning away from the red sequence. Description: Observations of each object were obtained from GALEX deep imaging collected as part of primary mission surveys. All objects were imaged by GALEX in the near-UV (NUV; 1750-2750Å) and far-UV (FUV; 1350-1750Å) bands. Cut-outs of the SDSS r-band FITS images and SDSS gri color composite images of each GALEX-SDSS matched object were generated using smosaic. Optical measurements (Petrosian magnitudes, R50, R90, and Galactic reddening) as well as stellar mass for each object were obtained from the MPA-JHU SDSS catalogs. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file table1.dat 95 561 Properties of sample galaxies table2.dat 41 80 Properties of XUV-disks and XUV-ambiguous galaxies
See also: J/A+A/544/A65 : GALEX Arecibo SDSS survey. VI. (Catinella+, 2012) J/ApJ/741/79 : The Spitzer-SDSS-GALEX Spectroscopic Survey (O'Dowd+, 2011) J/ApJ/731/28 : UV star-forming association in galaxies (Alberts+, 2011) J/AJ/140/1194 : FUV/HI relations in nearby galaxies (Bigiel+, 2010) J/AJ/140/1975 : Normal galaxies optical and UV photometry (Smith+, 2010) J/MNRAS/403/683 : GALEX Arecibo SDSS survey (GASS) (Catinella+, 2010) J/ApJS/173/538 : XUV-Disk galaxies in the Local Universe (Thilker+, 2007) J/ApJS/173/293 : UV-Optical galaxy color-magnitude diagram I. (Wyder+, 2007) J/A+AS/114/527 : UV properties of normal galaxies. III. (Rifatto+, 1995) : SDSS home page : GALEX GR6 archive : The MPA-JHU DR7 of spectrum web page Byte-by-byte Description of file: table1.dat
Bytes Format Units Label Explanations
1- 4 A4 --- --- [SDSS] 6- 24 A19 --- SDSS SDSS name ( 26- 33 F8.4 deg RAdeg Right Ascension in decimal degrees (J2000) 34 A1 --- --- [0] 36- 42 F7.4 deg DEdeg Declination in decimal degrees (J2000) 43 A1 --- --- [0] 45- 49 F5.3 --- z [0.003/0.05] Redshift 50 A1 --- --- [0] 52- 56 F5.1 ks NUVexp NUV exposure time 57 A1 --- --- [0] 59- 63 F5.1 ks FUVexp FUV exposure time 64 A1 --- --- [0] 66- 69 F4.2 mag NUV-r [0.04/6.42] The (NUV-r) color index 70 A1 --- --- [0] 72- 75 F4.2 mag FUV-r [0.55/8.7] The (FUV-r) color index 76 A1 --- --- [0] 78- 82 F5.2 mag rmag [12.17/18.51] SDSS r band magnitude 83 A1 --- --- [0] 85- 89 F5.2 [Msun] logM* [8/11.54] Log of the mass 90 A1 --- --- [0] 92- 95 F4.2 --- C Concentration index; C=R90/R50
Byte-by-byte Description of file: table2.dat
Bytes Format Units Label Explanations
1- 4 A4 --- --- [SDSS] 6- 24 A19 --- SDSS SDSS name ( 26- 31 F6.3 mag FUV-r(XUV) The (FUV-r) color of XUV region 33- 37 F5.2 --- R80/RXUV [0.1/26] The R80/RXUV ratio (1) 39 A1 --- Type [AD] Source type; D=XUV-disk, A=XUV-amb. 41 A1 --- Rej? [NY] Reject; Y=Reject, N=Non-reject
Note (1): In order to assess why a fraction of XUV disks and XUV-ambiguous galaxies have remarkably red XUV regions, we found the contour that includes 80% of the r-band light, R80. We define R80 as the mean of the projected major and minor axes of this contour. RXUV is the extent of the XUV threshold (also measured in projection). See section 4.4.2 and Figure 13 for further details.
History: From electronic version of the journal
(End) Greg Schwarz [AAS], Emmanuelle Perret [CDS] 09-Nov-2012
The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line

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