J/AJ/141/171 RR Lyrae stars in six ultra-deep fields of M31 (Jeffery+, 2011)
HST/ACS observations of RR Lyrae stars in six ultra-deep fields of M31.
Jeffery E.J., Smith E., Brown T.M., Sweigart A.V., Kalirai J.S.,
Ferguson H.C., Guhathakurta P., Renzini A., Rich R.M.
<Astron. J., 141, 171 (2011)>
=2011AJ....141..171J 2011AJ....141..171J
ADC_Keywords: Galaxies, nearby ; Stars, variable ; Photometry, HST
Keywords: galaxies: individual (M31) - galaxies: stellar content -
stars: variables: RR Lyrae
Abstract:
We present HST/ACS observations of RR Lyrae variable stars in six
ultra-deep fields of the Andromeda galaxy (M31), including parts of
the halo, disk, and giant stellar stream. Past work on the RR Lyrae
stars in M31 has focused on various aspects of the stellar populations
that make up the galaxy's halo, including their distances and
metallicities. This study builds upon this previous work by increasing
the spatial coverage (something that has been lacking in previous
studies) and by searching for these variable stars in constituents of
the galaxy not yet explored.
Description:
We obtained the data with HST/ACS with the primary goal of exploring
the star formation histories of six fields in M31 by observing to an
unprecedented depth, resolving stars below the main sequence turn off.
These observations represent over 300 HST orbits and 220.25hr of
imaging.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
stars.dat 74 56 *Properties of RR Lyrae and Cepheid stars
table9.dat 73 55 Properties of RR Lyrae stars found in the
halo11 field
photom.dat 35 5484 *Photometry of all RR Lyrae and Cepheids in
fields disk, stream, halo21 and halo35b
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Note on stars.dat: RR Lyrae found in the disk (table7), stream (table8),
and halo21 (table10) and halo35b (table11) fields, and Cepheids (table14).
Note on photom.dat: RR Lyrae in disk (table3), stream (table4), halo21 (table5),
halo35b (table6) fields, and Cepheids in disk (table12) and halo21 (table13)
fields.
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See also:
J/AJ/138/184 : RR Lyrae in 2 fields in M31 spheroid (Sarajedini+, 20
J/A+A/402/113 : (RI)c photometry of variables in M31 (Joshi+, 2003)
J/AJ/127/2738 : ACS VI photometry of M31 halo RR Lyrea (Brown+, 2004)
J/ApJS/184/152 : Deep optical photometry in M31 (Brown+, 2009)
J/ApJ/708/817 : RR Lyrae variables in M32 and M31 (Fiorentino+, 2010)
Byte-by-byte Description of file: stars.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Name Star number
7- 8 I2 h RAh Right ascension (J2000)
10- 11 I2 min RAm Right ascension (J2000)
13- 17 F5.2 s RAs Right ascension (J2000)
19 A1 --- DE- Declination sign (J2000)
20- 21 I2 deg DEd Declination (J2000)
23- 24 I2 arcmin DEm Declination (J2000)
26- 29 F4.1 arcsec DEs Declination (J2000)
31- 37 F7.4 d Per Period
39- 44 F6.3 mag F606W F606W intensity-weighted magnitude
46- 51 F6.3 mag F814W F814W intensity-weighted magnitude
53- 57 F5.3 mag A606 Amplitude in F606W band
59- 63 F5.3 mag A814 Amplitude in F814W band
65- 66 A2 --- Type Type of RR Lyr ("ab" or "c")
68- 74 A7 --- Field Field name
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Byte-by-byte Description of file: table9.dat
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Bytes Format Units Label Explanations
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1- 4 A4 --- VName Variable name <[BFS2004] VNNN> in Simbad
7- 8 I2 h RAh Right ascension (J2000)
10- 11 I2 min RAm Right ascension (J2000)
13- 17 F5.2 s RAs Right ascension (J2000)
19 A1 --- DE- Declination sign (J2000)
20- 21 I2 deg DEd Declination (J2000)
23- 24 I2 arcmin DEm Declination (J2000)
26- 29 F4.1 arcsec DEs Declination (J2000)
31- 37 F7.4 d Per Period
39- 44 F6.3 mag F606W F606W intensity-weighted magnitude
46- 51 F6.3 mag F814W F814W intensity-weighted magnitude
53- 57 F5.3 mag A606 Amplitude in F606W band
59- 63 F5.3 mag A814 Amplitude in F814W band
65- 66 A2 --- Type Type of RR Lyr ("ab", "c" or "d")
68- 73 A6 --- Field Field name
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Byte-by-byte Description of file: photom.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Name Star number
7- 16 F10.3 d MJD Modified Julian Date (JD-2400000.0)
18- 22 A5 --- Band Filter used in observation (F606W or F814W)
24- 29 F6.3 mag mag ?=99 Magnitude in Band (1)
31- 35 F5.3 mag e_mag ?=9 Error in mag (2)
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Note (1): A magnitude of 99.000 signifies missing data.
Note (2): An error value of 9.000 signifies missing data.
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History:
From electronic version of the journal
(End) Greg Schwarz [AAS], Patricia Vannier [CDS] 06-Sep-2012