CDROM/AJ/V108/P1987 The SSRS2 Sample (Alonso+ 1995) ================================================================================ CCD Calibration of the Magnitude Scale for the SSRS2 Sample: The Equatorial Region M. Victoria Alonso, L. Nicolaci da Costa, David W. Latham, Paulo S. Pellegrini, & Alejandra A. E. Milone <1994, AJ, 108, 1987> =1994AJ....108.1987A ================================================================================ Abstract: In this paper we continue our investigation on the isophotal nature, accuracy, and uniformity of the magnitude system adopted in the Southern Sky Redshift Survey extension (SSRS2). Extending our earlier work, we examine galaxies in the equatorial region, primarily in the declination range -17.5 deg <= Dec. <= 0 deg, over a large range of right ascension, covering the southern and northern Galactic caps. For this purpose, we have obtained CCD isophotal magnitudes in the B and R bands for 265 galaxies of different morphological types. Using this larger sample we confirm our earlier claim that the m(SSRS2) magnitudes are very nearly the magnitude measured within the isophote mu_B = 26 mag/arcsec^2, with a dispersion of about 0.30 mag. The relative zero-point offset between our m(SSRS2) magnitudes and CCD photometry is -0.02 mag from all data we have obtained. However, we detect a variation of the zero-point across different regions of the sky of +/- 0.10 mag for regions at large angular separations. We also estimate that the zero-point offset between the m(SSRS2) and Zwicky systems is relatively small (~0.10 mag), which should allow us to combine the data from the SSRS2 and the CfA2 Redshift Survey. File Summary: -------------------------------------------------------------------------------- File Name Lrecl Records Explanations -------------------------------------------------------------------------------- table1.dat 63 265 Galaxy sample notes1.dat 80 90 Notes to table 1 table2.dat 56 238 Isophotal magnitudes for observed galaxies table1.tex 86 543 TeX version of Table 1 and notes table2.tex 108 417 TeX version of Table 2 useful.tex 78 42 Macro package required by TeX files -------------------------------------------------------------------------------- Byte-by-byte Description of file: table1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1-12 A12 --- Galaxy Name of the galaxy 13-21 A9 --- StScI Space Telescope Science Institute Id. 22-24 I3 h RAh Right ascension 1950.0 25-27 I3 min RAm R.A. 28-32 F5.1 s RAs R.A. 33 1X --- --- Blank 34 A1 --- DE- Sign declination 35-36 I2 deg DEd Declination 1950.0 37-39 I3 arcmin DEm Dec. 40-42 I3 arcsec DEs Dec. 43-46 I4 --- Type []? Morph. type, Corwin 1993, private comm. 47-53 F7.2 mag mSSRS2 []? SSRS2 magnitude 54-59 F6.1 mag mMCG []? Morphological Cat. of Galaxies magnitude 60 1X --- --- Blank 61-63 A3 --- Note *Note flags -------------------------------------------------------------------------------- Notes for file: table1.dat -------------------------------------------------------------------------------- Note: 1 - Galaxies in common with ESO-LV. 2 - Galaxies in common with CGCG. 3 - Surface brightness profiles used in the comparisons with other authors. * - Comments on Individual Galaxies (see notes1.dat) -------------------------------------------------------------------------------- Byte-by-byte Description of file: notes1.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1-80 A80 --- Note Text of note for object marked with '*' in field 'Note' in table1.dat -------------------------------------------------------------------------------- Byte-by-byte Description of file: table2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1-12 A12 --- Galaxy Name of the galaxy 13 1X --- --- Blank 14-18 A5 --- Date Observation date 19-25 F7.2 mag mB26 *CCD magnitude m_B(26) 26-30 F5.2 mag e_mB26 Associated error in mB26 31-37 F7.2 mag mR26 *CCD magnitude m_R(26) 38-42 F5.2 mag e_mR26 Associated error in mR26 43-49 F7.2 --- muBlim Limiting blue isophote, mu_{B,lim} 50-56 F7.2 --- muRlim Limiting red isophote, mu_{R,lim} -------------------------------------------------------------------------------- Notes for file: table2.dat -------------------------------------------------------------------------------- mB26: CCD magnitude m_B(26) as measured within (or extrapolated to) the isophote mu_B = 26 mag/arcsec^2 mR26: CCD magnitude m_R(26) as extrapolated to the isophote mu_R = 26 mag/arcsec^2 -------------------------------------------------------------------------------- ================================================================================ (End) Lee Brotzman [ADS] 05-May-1995