J/ApJ/893/11 Massive star variability in M31 from iPTF (Soraisam+, 2020)
Variability of massive stars in M31 from the Palomar Transient Factory.
Soraisam M.D., Bildsten L., Drout M.R., Prince T.A., Kupfer T., Masci F.,
Laher R.R., Kulkarni S.R.
<Astrophys. J., 893, 11-11 (2020)>
=2020ApJ...893...11S 2020ApJ...893...11S (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby; Stars, giant; Spectral types; Photometry, RI;
Surveys
Keywords: Andromeda galaxy; Massive stars; Supergiant stars; Catalogs; Surveys
Abstract:
Using data from the (intermediate) Palomar Transient Factory (iPTF),
we characterize the time variability of ∼500 massive stars in M31. Our
sample is those stars that are spectrally typed by Massey and
collaborators, including Luminous Blue Variables, Wolf-Rayets, and
warm and cool supergiants. We use the high-cadence, long-baseline
(∼5yr) data from the iPTF survey, coupled with data-processing tools
that model complex features in the light curves. We find widespread
photometric (R-band) variability in the upper Hertzsprung Russell
diagram (or CMD) with an increasing prevalence of variability with
later spectral types. Red stars (V-I>1.5) exhibit larger amplitude
fluctuations than their bluer counterparts. We extract a
characteristic variability timescale, tch, via wavelet
transformations that are sensitive to both continuous and localized
fluctuations. Cool supergiants are characterized by longer timescales
(>100 days) than the hotter stars. The latter have typical timescales
of tens of days but cover a wider range, from our resolution limit of
a few days to longer than 100 days. Using a 60 night block of data
straddling two nights with a cadence of around 2 minutes, we extracted
tch in the range 0.1-10 days with amplitudes of a few percent for
13 stars. Though there is broad agreement between the observed
variability characteristics in the different parts of the upper CMD
with theoretical predictions, detailed comparison requires models with
a more comprehensive treatment of the various physical processes
operating in these stars, such as pulsation, subsurface convection,
and the effect of binary companions.
Description:
We perform the variability analysis of massive stars in M31 using two
complementary data sets: (1) a catalog of spectroscopically typed
luminous stars in M31 (Massey+, 2016, J/AJ/152/62) and (2) data from
the long-baseline optical time-domain survey of M31 by PTF.
The (intermediate) PTF survey provides a rich optical time-domain data
set for M31 (Soraisam+ 2017A&A...599A..48S 2017A&A...599A..48S), with almost daily sampling for
about five years. We use the same iPTF/PTF data set in the R-band as
in Paper I (Soraisam+, 2018, J/ApJ/859/73).
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 99 491 Variability characteristics of massive stars in M31
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See also:
II/264 : ASAS Variable Stars in Southern hemisphere (Pojmanski+, 2002-2005)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
I/347 : Distances to 1.33 billion stars in Gaia DR2 (Bailer-Jones+, 2018)
J/A+A/366/508 : S Dor variables (van Genderen+, 2001)
J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)
J/AJ/134/2474 : Ha emission-line stars in 7 dwarfs galaxies (Massey+, 2007)
J/AJ/140/14 : Variability of luminous stars in LMC (Szczygiel+, 2010)
J/A+A/509/A70 : Study of an eclipsing binary in M31 (Vilardell+, 2010)
J/ApJ/727/53 : Red supergiant stars in the LMC. I. (Yang+, 2011)
J/ApJ/759/11 : Wolf-Rayet content of M31 (Neugent+, 2012)
J/other/Sci/337.444 : RV curves of Galactic massive O stars (Sana+, 2012)
J/ApJ/754/35 : Red supergiant stars in the SMC. II. (Yang+, 2012)
J/other/ApSS/345.133 : Photometric variability of WR 103 (van Genderen+, 2013)
J/A+A/562/A125 : OGLE-III SMC massive stars VI light curves (Kourniotis+, 2014)
J/ApJ/789/10 : M33 WR and Of-type Stars (Neugent+, 2014)
J/A+A/570/A3 : Optical spectrum of HD50975 (Sperauskas+, 2014)
J/A+A/580/A93 : VLTS. B stars multiplicity (Dunstall+, 2015)
J/ApJ/826/224 : RSG and foreground candidates in M31 (Massey+, 2016)
J/AJ/152/62 : Revised LGGS UBVRI phot. of M31 and M33 stars (Massey+, 2016)
J/ApJ/844/40 : Variable stars in M31 & M33. V. HR diagram (Humphreys+, 2017)
J/ApJ/859/140 : Multi-band magnitudes for W UMa EB* candidates (Chen+, 2018)
J/ApJ/864/111 : HST/ACS one-year observations of M51 stars (Conroy+, 2018)
J/ApJ/859/73 : Variability of RSGs in M31 from iPTF (Soraisam+, 2018)
J/A+A/618/A185 : VI magnitudes of NGC 4535 stars (Spetsieri+, 2018)
J/A+A/623/A110 : Gaia DR2. Variable stars in CMD (Gaia Collaboration+, 2019)
J/A+A/624/A129 : 30 Dor red supergiant stars radial velocities (Patrick+, 2019)
J/ApJ/872/L9 : TESS obs. of massive O and B stars (Pedersen+, 2019)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- LGGS Star identifier (JHHMMSS.ss+DDMMSS.s) (1)
20 A1 --- m_LGGS LGGS component for J004147.24+410647.5 (1)
22- 35 A14 --- SpT Spectral classification (1)
37- 41 F5.2 mag Rmag [14.8/20] PTF R-band mean magnitude of
the lightcurve
43- 46 F4.2 mag RMS [0.01/0.7] RMS value of the lightcurve
48- 99 A52 d Timescale Characteristic timescale tch (2)
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Note (1): IDs and spectral classification from the Local Group Galaxy Survey
(LGGS; Massey+, 2016, J/AJ/152/62). See Section 2.1.
Note (2): Measurements not available are indicated with -99.
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History:
From electronic version of the journal
References:
Soraisam et al. Paper I. 2018ApJ...859...73S 2018ApJ...859...73S Cat. J/ApJ/859/73
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 02-Sep-2021