J/ApJ/324/172 M31 UBVR photometry (Hodge+, 1988)
UBVR CCD photometry of stars in M 31. I. Baade's field IV
Hodge P., Lee M.G., Mateo M.
<Astrophys. J. 324, 172 (1988)>
=1988ApJ...324..172H 1988ApJ...324..172H (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, photometry ; Photometry, CCD
Keywords: galaxies: individual (M 31) - galaxies: photometry -
galaxies: stellar content- luminosity function
Description:
We report deep UBVR CCD photometry of stars in a portion of an arm of
M 31, 20kpc southwest of the nucleus. The color-magnitude diagram
shows a main sequence that reaches from Mv=-0.7 (at our photometric
limit) to Mv=-6.2 and a well-populated giant region. The R, B-R
diagram separates the stars rather clearly into three groups, the main
sequence, intermediate-color stars (which include the brighter
foreground stars), and the red giants. Reddening is found to average
E(B-V)=0.13±0.04. To determine a reliable luminosity function, we
have eliminated foreground contamination and have evaluated our
sample completeness, using a large number of artificial stars in the
DAOPHOT reduction routine. The corrected luminosity function, which
extends from Mv=-5 to -1, has a logarithmic slope of 0.57±0.07 for
all stars and 0.53±0.06 for main-sequence stars only. This value is
similar to that reported for galaxies in general
(Freedman 1985ApJ...299...74F 1985ApJ...299...74F and 1986, IAUS 116, 61).
Objects:
-----------------------------------------
RA (2000) DE Designation(s)
-----------------------------------------
00 42.7 +41 16 M 31 = NGC 224
-----------------------------------------
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1 80 695 Results of UBVR CCD photometry
--------------------------------------------------------------------------------
Byte-by-byte Description of file: table1
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 I3 --- Star Star number
5- 10 F6.2 pix Xpos X position (1)
12- 17 F6.2 pix Ypos Y position (1)
19- 24 F6.3 mag Vmag V magnitude
26- 30 F5.3 mag e_Vmag rms uncertainty on Vmag
32- 37 F6.3 mag B-V ? B-V color index
39- 43 F5.3 mag e_B-V ? rms uncertainty on B-V
45- 50 F6.3 mag U-B ? U-B color index
52- 56 F5.3 mag e_U-B ? rms uncertainty on U-B
59- 64 F6.3 mag V-R ? V-R color index
66- 70 F5.3 mag e_V-R ? rms uncertainty on V-R
--------------------------------------------------------------------------------
Note (1): Increasing left to right, bottom to top, in Fig. 2.
--------------------------------------------------------------------------------
References:
Hodge P. & Lee M.G., Paper II. 1988, ApJ 329, 651 =1988ApJ...329..651H 1988ApJ...329..651H
History: Prepared via OCR at CDS.
(End) Marie-Jose Wagner, Patricia Bauer [CDS] 30-Sep-1996