J/ApJS/154/623 M31 Long Period Variables : Photometry (Mould+, 2004)
The period-luminosity relation for long-period variables in M31.
Mould J., Saha A., Hughes S.
<Astrophys. J. Suppl. Ser., 154, 623-631 (2004)>
=2004ApJS..154..623M 2004ApJS..154..623M
ADC_Keywords: Stars, variable ; Photometry, Cousins ; Photometry, infrared
Keywords: galaxies: individual (M31) - infrared: stars -
stars: AGB and post-AGB - stars: variables: other
Abstract:
A significant fraction of the disk of M31 has been surveyed for
long-period variable stars. We report the results, including
near-infrared photometry of almost 2000 variables, and light curves in
the i band. The period-luminosity relation suggests that most of the
variables are asymptotic giant branch stars, and their luminosity
function can be understood in terms of mass-loss rates, which increase
with increasing luminosity on the giant branch, and star formation
rates, which were a few times higher a billion years ago in M31 than
they are today. We see some supergiant long-period variables, but
somewhat fewer than expected based on their frequency in M33, and
confined to the ring of star formation in M31 seen in the IRAS and
2MASS surveys.
Description:
The observations upon which this paper is based were taken over a
period of more than 6yr from Palomar Observatory. We surveyed 64
fields in M31 with the 60inch telescope, equipped with a refractive
reimager including an f/1.2 camera and a TI 800x800 CCD. The pixel
scale was approximately 0.6"/pixel and exposure times were 5minutes
per field, to avoid saturation of the brightest LPVs. All observations
were made in the I band, usually close to full moon.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 60 1911 M31 LPVs - Photometry
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See also:
J/A+A/402/113 : (RI)c photometry of variables in M31 (Joshi+, 2003)
J/A+A/421/509 : AGAPE catalogue of M31 variables (Ansari+, 2004)
J/MNRAS/351/1071 : POINT-AGAPE Survey. M31 variables (An+, 2004)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- [MSH2004] Identification number (1)
7- 14 F8.5 deg RAdeg Right Ascension in decimal degrees (J2000)
16- 23 F8.5 deg DEdeg Declination in decimal degrees (J2000)
25- 27 I3 d Per Period
28 A1 --- f_Per [*] Flag on Per (2)
30- 33 F4.1 mag imag The i band magnitude (approximate
calibration on to the Cousins system)
35- 39 F5.2 mag Jmag ?=99.99 The J band magnitude
41- 42 I2 10-2mag e_Jmag ?=-9 Error in Jmag
44- 48 F5.2 mag Hmag ?=99.99 The H band magnitude
50- 51 I2 10-2mag e_Hmag ?=-9 Error in Hmag
53- 57 F5.2 mag Kmag ?=99.99 The K band magnitude
59- 60 I2 10-2mag e_Kmag ?=-9 Error in Kmag
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Note (1): The field number is indicated in the first two digits of these
LPV numbers.
Note (2): An asterisk in the period column indicates a variable which is
probably not an LPV.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Marianne Brouty [CDS] 07-Feb-2005