J/AJ/127/704 Low surface brightness galaxies in SDSS (Kniazev+, 2004) ================================================================================ Low surface brightness galaxies in the Sloan Digital Sky Survey. I. Search method and test sample. Kniazev A.Y., Grebel E.K., Pustilnik S.A., Pramskij A.G., Kniazeva T.F., Prada F., Harbeck D. =2004AJ....127..704K ================================================================================ ADC_Keywords: Galaxies, photometry ; Photometry, SDSS ; Photometry, surface Keywords: galaxies: fundamental parameters - galaxies: irregular - galaxies: photometry - galaxies: spiral - galaxies: structure - methods: data analysis Abstract: In this paper we present results of a pilot study to use imaging data from the Sloan Digital Sky Survey (SDSS) to search for low surface brightness (LSB) galaxies. For our pilot study we use a test sample of 92 galaxies from the Impey et al. catalog distributed over 93 SDSS fields of the Early Data Release (EDR, ). Many galaxies from the test sample are either LSB or dwarf galaxies. To deal with the SDSS data most effectively, a new photometry software was created, which is described in this paper. We present the results of the selection algorithms applied to these 93 EDR fields. Two galaxies from the Impey et al. (1996, ) test sample are very likely artifacts, as confirmed by follow-up imaging. With our algorithms we were able to recover 87 of the 90 remaining test sample galaxies, implying a detection rate of ~96.5%. The three missed galaxies fall too close to very bright stars or galaxies. In addition, 42 new galaxies with parameters similar to the test sample objects were found in these EDR fields (i.e.,~47% additional galaxies). We present the main photometric parameters of all identified galaxies and carry out first statistical comparisons. We tested the quality of our photometry by comparing the magnitudes for our test sample galaxies and other bright galaxies with values from the literature. All these tests yielded consistent results. We briefly discuss a few unusual galaxies found in our pilot study, including an LSB galaxy with a two-component disk and 10 new giant LSB galaxies. File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table1.dat 124 129 The general parameters of large-angular-size galaxies identified in the fields of the test subsample table2.dat 108 129 Total magnitudes and model-independent parameters of large-angular-size galaxies identified in the test fields table3.dat 144 110 Model-dependent photometric parameters of large-angular-size galaxies identified in the test fields table4.dat 110 14 Model-dependent photometric parameters of large-angular-size galaxies with Sersic profiles identified in the test fields table5.dat 74 6 The photometric repeatability table6.dat 54 11 Giant LSB spiral galaxies from our sample -------------------------------------------------------------------------------- See also: J/AJ/123/567 : SDSS quasar catalog, I: Early Data Release (Schneider+, 2002) J/ApJS/105/209 : Low surface brightness galaxies. I. The catalog (Impey+ 1996) Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 I3 --- Seq Running identification number 5- 8 A4 --- --- [SDSS] 10- 23 A14 --- SDSS SDSS name (1) 25- 33 A9 --- ISI96 Impey et al. (1996, J/ApJS/105/209) name (2) 35- 36 I2 h RAh Hour of Right Ascension (J2000) 38- 39 I2 min RAm Minute of Right Ascension (J2000) 41- 45 F5.2 s RAs Second of Right Ascension (J2000) 47 A1 --- DE- Sign of the Declination (J2000) 48- 49 I2 deg DEd Degree of Declination (J2000) 51- 52 I2 arcmin DEm Arcminute of Declination (J2000) 54- 58 F5.2 arcsec DEs Arcsecond of Declination (J2000) 60- 62 I3 --- SDSSrun SDSS image run number 64 I1 --- SDSScol SDSS image column 66- 68 I3 --- SDSSfield SDSS image field 70- 74 F5.2 mag Bmag Apparent B band magnitude (3) 76- 79 F4.2 mag e_Bmag Error in Bmag (3) 81- 84 F4.2 mag B-V (B-V) color (4) 86- 91 F6.2 mag BMAG ? Absolute B band magnitude (5) 93- 97 I5 km/s HRV ? Heliocentric velocity (6) 99-104 A6 --- MType Morphological classification (7) 106-123 A18 --- OName Other NED names -------------------------------------------------------------------------------- Note (1): Based on the equatorial coordinates for equinox J2000. Note (2): If not from Impey et al. (1996, ), this entry is blank. Note (3): Recalculated from g^*^ and r^*^ integrated magnitudes using of equations from Smith et al. (2002AJ....123.2121S). Note (4): Calculated from g^*^ and r^*^ magnitudes using the respective equations from Smith et al. (2002AJ....123.2121S). Note (5): Calculated from Bmag in the previous column and the distance derived from the known heliocentric velocities, assuming a Hubble flow with H_0_=75km/s/Mpc, with no corrections for the motion of the Sun and Local Group. No corrections have been made for Galactic foreground extinction. Note (6): Taken from Impey et al. (1996, ), from the SDSS EDR (J/AJ/123/567) database and the NASA/IPAC Extragalactic Database (NED) Note (7): In the system of de Vaucouleurs et al. (1991, ). This classification was based on that suggested in Impey et al. (1996, J/ApJS/105/209) and NED, where applicable. However, accounting for the superb quality of the SDSS images relative to most of the previously available data, we have checked the classification for all sample galaxies and revised it in a number of cases. For the remaining galaxies the classification was also done by the authors. -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 3 I3 --- Seq Running identification number 5- 8 A4 --- --- [SDSS] 10- 23 A14 --- SDSS SDSS name (G1) 25- 29 F5.2 mag u*mag ? SDSS u* band integrated magnitude 31- 34 F4.2 mag e_u*mag ? Error in u*mag 36- 40 F5.2 mag g*mag SDSS g* band integrated magnitude 42- 45 F4.2 mag e_g*mag Error in g*mag 47- 51 F5.2 mag r*mag SDSS r* band integrated magnitude 53- 56 F4.2 mag e_r*mag Error in r*mag 58- 62 F5.2 mag i*mag SDSS i* band integrated magnitude 64- 67 F4.2 mag e_i*mag Error in i*mag 69- 73 F5.2 mag z*mag SDSS z* band integrated magnitude 75- 78 F4.2 mag e_z*mag Error in z*mag 80- 83 F4.2 --- b/a Axis ratio 85- 87 I3 deg PA [-90/90] Position angle 89- 92 F4.1 arcsec Reff r band effective radius 94- 97 F4.1 mag/arcsec2 mueff(r) r band mean surface brightness inside Reff 99-101 F3.1 --- CI r band concentration index 103-107 F5.1 arcsec A26.2 r band size at SB=26.2mag/arcsec^2^ -------------------------------------------------------------------------------- Byte-by-byte Description of file: table3.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 14 A14 --- SDSS SDSS name (G1) 16- 20 F5.2 mag/arcsec2 mu0d(g*) g* band disk surface brightness 22- 25 F4.2 mag/arcsec2 e_mu0d(g*) Error in mu0d(g*) 27- 31 F5.2 arcsec alphad(g*) g* band disk scale length 33- 36 F4.2 arcsec e_alphad(g*) Error in alphad(g*) 38- 42 F5.2 mag/arcsec2 mu0b(g*) ? g* band bulge surface brightness 44- 47 F4.2 mag/arcsec2 e_mu0b(g*) ? Error in mu0b(g*) 49- 52 F4.2 arcsec alphab(g*) ? g* band bulge scale length 54- 57 F4.2 arcsec e_alphab(g*) ? Error in alphab(g*) 59- 63 F5.2 mag/arcsec2 mu0d(r*) r* band disk surface brightness 65- 68 F4.2 mag/arcsec2 e_mu0d(r*) Error in mu0d(r*) 70- 74 F5.2 arcsec alphad(r*) r* band disk scale length 76- 79 F4.2 arcsec e_alphad(r*) Error in alphad(r*) 81- 85 F5.2 mag/arcsec2 mu0b(r*) ? r* band bulge surface brightness 87- 90 F4.2 mag/arcsec2 e_mu0b(r*) ? Error in mu0b(r*) 92- 95 F4.2 arcsec alphab(r*) ? r* band bulge scale length 97-100 F4.2 arcsec e_alphab(r*) ? Error in alphab(r*) 102-106 F5.2 mag/arcsec2 mu0d(i*) i* band disk surface brightness 108-111 F4.2 mag/arcsec2 e_mu0d(i*) Error in mu0d(i*) 113-117 F5.2 arcsec alphad(i*) i* band disk scale length 119-122 F4.2 arcsec e_alphad(i*) Error in alphad(i*) 124-128 F5.2 mag/arcsec2 mu0b(i*) ? i* band bulge surface brightness 130-133 F4.2 mag/arcsec2 e_mu0b(i*) ? Error in mu0b(i*) 135-138 F4.2 arcsec alphab(i*) ? i* band bulge scale length 140-143 F4.2 arcsec e_alphab(i*) ? Error in alphab(i*) -------------------------------------------------------------------------------- Byte-by-byte Description of file: table4.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 14 A14 --- SDSS SDSS name (G1) 16- 20 F5.2 mag/arcsec2 mu0(g*) g* band surface brightness 22- 25 F4.2 mag/arcsec2 e_mu0(g*) rms uncertainty on mu0(g*) 27- 31 F5.2 arcsec alpha(g*) g* band scale length 33- 36 F4.2 arcsec e_alpha(g*) rms uncertainty on alpha(g*) 38- 41 F4.2 --- n(g*) g* band Sersic number 43- 46 F4.2 --- e_n(g*) rms uncertainty on n(g*) 48- 52 F5.2 mag/arcsec2 mu0(r*) r* band surface brightness 54- 57 F4.2 mag/arcsec2 e_mu0(r*) rms uncertainty on mu0(r*) 59- 63 F5.2 arcsec alpha(r*) r* band scale length 65- 68 F4.2 arcsec e_alpha(r*) rms uncertainty on alpha(r*) 70- 73 F4.2 --- n(r*) r* band Sersic number 75- 78 F4.2 --- e_n(r*) rms uncertainty on n(r*) 80- 84 F5.2 mag/arcsec2 mu0(i*) i* band surface brightness 86- 89 F4.2 mag/arcsec2 e_mu0(i*) rms uncertainty on mu0(i*) 91- 95 F5.2 arcsec alpha(i*) i* band scale length 97-100 F4.2 arcsec e_alpha(i*) rms uncertainty on alpha(i*) 102-105 F4.2 --- n(i*) i* band Sersic number 107-110 F4.2 --- e_n(i*) rms uncertainty on n(i*) -------------------------------------------------------------------------------- Byte-by-byte Description of file: table5.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 A4 --- --- [SDSS] 6- 19 A14 --- SDSS SDSS name (G1) 21- 25 F5.2 mag u*mag u* magnitude 27- 30 F4.2 mag e_u*mag rms uncertainty on u*mag 32- 36 F5.2 mag g*mag g* magnitude 38- 41 F4.2 mag e_g*mag rms uncertainty on g*mag 43- 47 F5.2 mag r*mag r* magnitude 49- 52 F4.2 mag e_r*mag rms uncertainty on r*mag 54- 58 F5.2 mag i*mag i* magnitude 60- 63 F4.2 mag e_i*mag rms uncertainty on i*mag 65- 69 F5.2 mag z*mag z* magnitude 71- 74 F4.2 mag e_z*mag rms uncertainty on u*mag -------------------------------------------------------------------------------- Byte-by-byte Description of file: table6.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 4 A4 --- --- [SDSS] 6- 19 A14 --- SDSS SDSS name (G1) 21- 29 A9 --- ISI96 Impey et al. (1996, ) name 31- 36 F6.2 mag BMAGd Disk absolute B magnitude 38- 42 F5.2 mag/arcsec2 mu0c(B) Central Surface brightness in B band 44- 48 F5.2 kpc alpha Scale length 50- 54 F5.2 --- DIndex Diffuseness index [mu0c(B)+5log(alpha)] -------------------------------------------------------------------------------- Global notes: Note (G1): Based on the equatorial coordinates for equinox J2000. -------------------------------------------------------------------------------- History: * 19-May-2004: from electronic version of the journal * 25-Mar-2006: table1, records #72 and 98, column OName: VV635 is a misprint for VV 655, UGC8784 is a misprint for UGC8474 ================================================================================ (End) Greg Schwarz [AAS], Patricia Vannier [CDS] 19-May-2004