J/AJ/161/79 Red supergiant stars in M31 and M33 (Massey+, 2021)
The Red Supergiant Content of M31 and M33.
Massey P., Neugent K.F., Levesque E.M., Drout M.R., Courteau S.
<Astron. J., 161, 79 (2021)>
=2021AJ....161...79M 2021AJ....161...79M
ADC_Keywords: Galaxies; Stars, supergiant; Photometry, infrared;
Effective temperatures; Cross identifications; Spectral types
Keywords: Massive stars ; Red supergiant stars ; Stellar evolution ;
Andromeda Galaxy ; Triangulum Galaxy
Abstract:
We identify red supergiants (RSGs) in our spiral neighbors M31 and M33
using near-IR (NIR) photometry complete to a luminosity limit of
logL/L☉=4.0. Our archival survey data cover 5°2 of M31, and
3°2 for M33, and are likely spatially complete for these massive
stars. Gaia is used to remove foreground stars, after which the RSGs
can be separated from asymptotic giant branch (AGB) stars in the
color-magnitude diagram. The photometry is used to derive effective
temperatures and bolometric luminosities via MARCS stellar atmosphere
models. The resulting H-R diagrams show superb agreement with the
evolutionary tracks of the Geneva evolutionary group. Our census
includes 6400 RSGs in M31 and 2850 RSGs in M33 within their Holmberg
radii; by contrast, only a few hundred RSGs are known so far in the
Milky Way. Our catalog serves as the basis for a study of the RSG
binary frequency being published separately, as well as future studies
relating to the evolution of massive stars. Here we use the matches
between the NIR- selected RSGs and their optical counterparts to show
that the apparent similarity in the reddening of OB stars in M31 and
M33 is the result of Malmquist bias; the average extinction in M31 is
likely higher than that of M33. As expected, the distribution of RSGs
follows that of the spiral arms, while the much older AGB population
is more uniformly spread across each galaxy's disk.
Description:
The images for M31 were taken with the wide-field NIR camera WIRCam on
the 3.6m Canada-France-Hawaii Telescope located atop Maunakea. The
data set consists of 70 usable J- and Ks-band image pairs. The data
were taken in queue mode during four blocks of time: 9 nights during
(UT) 2007 August 1 to September 23 (27 fields), 12 nights during 2009
August 6 to October 28 (12 fields), 4 nights during 2011 September 18
to October 9 (4 fields), and 6 nights during 2012 October 6 to 29 (27
fields). Each field was observed in 16x47s exposures in J and 26x25s
exposures in Ks.
The data for M33 were taken under program U/05B/7 with the Wide Field
Camera (WFCam) on the 3.8m United Kingdom Infrared Telescope (UKIRT)
located on Maunakea. Five tiles centered on M33 were observed, with
some overlap, resulting in a coverage of 3°2. The equivalent
exposure times were 150s in J and 270s in Ks. The data were taken in
queue mode on (UT) 2005 September 29 to 30, October 24, November 5,
and December 16.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 123 38817 Photometrically Selected RSGs in M31
table4.dat 124 7088 Photometrically Selected RSGs in M33
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See also:
II/236 : UBVR CCD survey of the Magellanic clouds (Massey+, 2002)
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/345 : Gaia DR2 (Gaia Collaboration, 2018)
J/ApJS/89/85 : Blue and red supergiants in M33 (Ivanov+ 1993)
J/ApJ/501/153 : VRB photometry of red supergiants (Massey 1998)
J/AJ/126/2867 : Red supergiants in Magellanic Clouds (Massey+, 2003)
J/AJ/129/729 : CCD photometry of luminous stars in M33 (Rowe+, 2005)
J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)
J/ApJ/671/781 : Red supergiants in Sct-Cru Galactic arm (Davies+, 2007)
J/AJ/133/2393 : UBVRI phot. in 7 Local Group galaxies (Massey+, 2007)
J/A+A/487/131 : JHKs photometry of LPVs in M33 (Cioni+, 2008)
J/ApJ/703/441 : Yellow supergiants in M31 (Drout+, 2009)
J/ApJ/703/420 : Red supergiants in M31 (Massey+, 2009)
J/AJ/142/103 : Cool evolved stars in SAGE-SMC and SAGE-LMC (Boyer+,2011)
J/ApJ/733/123 : The Wolf-Rayet content of M33 (NGC 598) (Neugent+, 2011)
J/ApJ/750/97 : The yellow and red supergiants of M33 (Drout+, 2012)
J/A+A/537/A146 : Stellar models rot. 0.8<M<120, Z=0.014 (Ekstrom+, 2012)
J/ApJ/749/177 : Yellow and red supergiants in the LMC (Neugent+, 2012)
J/other/Sci/337.444 : RV curves of Galactic massive O stars (Sana+, 2012)
J/ApJ/758/133 : Metallicity prof. M31 HII regions & PNe (Sanders+,2012)
J/A+A/578/A3 : New survey supergiants in MCs (Gonzalez-Fernandez+, 2015)
J/ApJ/826/224 : RSG and foreground candidates in M31 (Massey+, 2016)
J/AJ/152/62 : LGGS UBVRI photometry of M31 and M33 stars (Massey+,2016)
J/MNRAS/475/2003 : Red supergiant population in Perseus arm (Dorda+, 2018)
J/A+A/616/A12 : Gaia DR2 sources in GC & dSph (Gaia Collaboration+,2018)
J/A+A/609/A114 : Local Group AGB & red supergiants (Groenewegen+, 2018)
J/A+A/629/A91 : A source catalog for the SMC (Yang+, 2019)
Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Name [1/38817] M31RSG identification
7- 8 I2 h RAh [0] Hour of Right Ascension (J2000)
10- 11 I2 min RAm [36/50] Minute of Right Ascension (J2000)
13- 18 F6.3 s RAs Second of Right Ascension (J2000)
20- 20 A1 --- DE- [+] Sign of the Declination (J2000)
21- 22 I2 deg DEd [39/43] Degree of Declination (J2000)
24- 25 I2 arcmin DEm Arcminute of Declination (J2000)
27- 31 F5.2 arcsec DEs Arcsecond of Declination (J2000)
33- 36 F4.2 --- Rho [0.06/2.84] Galactocentric distance
(Holmberg radii) (1)
38- 43 F6.3 mag Ksmag [6.14/17.5] Ks magnitude
45- 50 F6.3 mag e_Ksmag [0.001/0.9] Ks error
52- 57 F6.3 mag Jmag-Ksmag [0.83/1.9] J-Ks magnitude
59- 64 F6.3 mag e_Jmag-Ksmag [0.001/1.1] J-Ks error
66- 67 I2 --- nObs [0/4] Number of observations
69- 69 I1 --- Flag-Gaia [0/2] Membership based upon Gaia (2)
71- 75 F5.2 mag Av [0.75/11.28] Adopted V-band extinction
77- 81 I5 K Teff [3450/6950] Effective temperature (3)
83- 86 F4.2 [Lsun] LogLum [3.61/9.51] Log luminosity, solar units (4)
88-107 A20 --- LGGS LGGS Name (if any)
109-113 F5.2 mag Vmag [17.25/24.06]? LGGS V mag (if any)
115-123 A9 --- SpType LGGS Spectral type (if any)
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Note (1): Assumes Holmberg radius of 95.3arcmin, inclination 77.0deg, and
a position angle of the major axis of 35.0deg. At a distance of 760kpc,
a ρ of 1.00 corresponds to 21.07kpc.
Note (2): Flag as follows:
0 = probable member; 2011 occurrences
1 = membership uncertain; 3922 occurrences
2 = incomplete or no Gaia data; 32884 occurrences
Note (3): Typical uncertainity 150K.
Note (4): Typical uncertainity 0.05dex.
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Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 5 I5 --- Name [1/7088] M33RSG identification
7- 8 I2 h RAh [1] Hour of Right Ascension (J2000)
10- 11 I2 min RAm [29/37] Minute of Right Ascension (J2000)
13- 17 F5.2 s RAs Second of Right Ascension (J2000)
20- 20 A1 --- DE- [+] Sign of the Declination (J2000)
21- 22 I2 deg DEd [29/31] Degree of Declination (J2000)
24- 25 I2 arcmin DEm Arcminute of Declination (J2000)
27- 30 F4.1 arcsec DEs Arcsecond of Declination (J2000)
33- 36 F4.2 --- Rho [0.01/3.88] Galactocentric distance
(Holmberg radii) (1)
38- 43 F6.3 mag Ksmag [12.6/17.5] Ks magnitude
45- 50 F6.3 mag e_Ksmag [0.001/0.2] Ks error
52- 57 F6.3 mag Jmag-Ksmag [0.78/1.79] J-Ks magnitude
59- 64 F6.3 mag e_Jmag-Ksmag [0.002/0.2] J-Ks error
66- 67 I2 --- nObs [0/16] Number of observations
69- 69 I1 --- Flag-Gaia [0/2] Membership based upon Gaia (2)
71- 75 F5.2 mag Av [0.75/4.46] Adopted V-band extinction
77- 81 I5 K Teff [3600/4750] Effective temperature (3)
83- 86 F4.2 [Lsun] LogLum [3.74/6.02] Log luminosity, solar units (4)
88-107 A20 --- LGGS LGGS Name (if any)
109-113 F5.2 mag Vmag [16.97/23.38]? LGGS V mag (if any)
115-124 A10 --- SpType LGGS Spectral type (if any)
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Note (1): Assumes Holmberg radius of 95.3arcmin, inclination 77.0deg, and
a position angle of the major axis of 35.0deg. At a distance of 760kpc,
a ρ of 1.00 corresponds to 21.07kpc.
Note (2): Flag as follows:
0 = probable member; 1827 occurrences
1 = membership uncertain; 2033 occurrences
2 = incomplete or no Gaia data; 3228 occurrences
Note (3): Typical uncertainity 150K.
Note (4): Typical uncertainity 0.05dex.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 06-Apr-2021