J/ApJ/889/44 UKIRT obs. of red supergiants in M31 (Neugent+, 2020)
The luminosity function of red supergiants in M31.
Neugent K.F., Massey P., Georgy C., Drout M.R., Mommert M., Levesque E.M.,
Meynet G., Ekstrom S.
<Astrophys. J., 889, 44 (2020)>
=2020ApJ...889...44N 2020ApJ...889...44N
ADC_Keywords: Galaxies, nearby; Photometry, infrared; Stars, giant
Keywords: Massive stars ; Red supergiant stars ; Stellar mass loss ;
Andromeda Galaxy ; Luminosity function
Abstract:
The mass-loss rates of red supergiant stars (RSGs) are poorly
constrained by direct measurements, and yet the subsequent evolution
of these stars depends critically on how much mass is lost during the
RSG phase. In 2012 the Geneva evolutionary group updated their
mass-loss prescription for RSGs with the result that a 20M☉ star
now loses 10 times more mass during the RSG phase than in the older
models. Thus, higher-mass RSGs evolve back through a second yellow
supergiant phase rather than exploding as Type II-P supernovae, in
accord with recent observations (the so-called "RSG Problem"). Still,
even much larger mass-loss rates during the RSG phase cannot be ruled
out by direct measurements of their current dust-production rates, as
such mass loss is episodic. Here, we test the models by deriving a
luminosity function for RSGs in the nearby spiral galaxy, M31, which
is sensitive to the total mass loss during the RSG phase. We carefully
separate RSGs from asymptotic giant branch stars in the
color-magnitude diagram following the recent method exploited by
Yang+ (2019, J/A+A/629/A91) in their Small Magellanic Cloud studies.
Comparing our resulting luminosity function with that predicted by the
evolutionary models shows that the new prescription for RSG mass loss
does an excellent job of matching the observations, and we can readily
rule out significantly larger values.
Description:
All of the J and K photometry comes from new images taken with the
Wide Field Camera (WFCAM) on the 3.8m United Kingdom Infrared
Telescope (UKIRT) located on Maunakea, Hawai'i. The data were obtained
as part of the UKIRT Service Program (Proposal U/17B/UA03) between
2017 Dec 8 and 2018 Jan 6.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 65 198441 *UKIRT photometry M31 fields A and B
table3.dat 65 8220 *UKIRT photometry M31 control field
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Note on table2.dat and table3.dat: We selected two M31 fields and one
nearby "control" field as shown in Figure 3 and Table 1:
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Field RA (J2000) DE Date Date Area Nstars
Visit 1 Visit 2 deg2
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A 0 40 12 +40 42 00 2017 Dec 08 2017 Dec 11 0.54 116498
B 0 45 36 +42 00 00 2017 Dec 30 2018 Jan 6 0.72 132623
Control 0 35 24 +41 24 00 2017 Dec 12 2017 Dec 28 0.72 11057
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Note: Nstars includes some saturated stars that were removed in the analysis.
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
II/311 : WISE All-Sky Data Release (Cutri+ 2012)
J/A+AS/96/269 : Stellar Models from 0.8 to 120 Msolar (Schaller+, 1992)
J/A+A/333/231 : O-M stars model atmospheres (Bessell+ 1998)
J/A+A/357/225 : Mass loss of M supergiants (Josselin+, 2000)
J/AJ/126/2867 : Red supergiants in Magellanic Clouds (Massey+, 2003)
J/AJ/133/2393 : UBVRI phot. in 7 Local Group dwarfs galaxies (Massey+, 2007)
J/ApJ/703/441 : Yellow supergiants in M31 (Drout+, 2009)
J/ApJ/703/420 : Red supergiants in M31 (Massey+, 2009)
J/MNRAS/395/1409 : Type II-P SN progenitor constraints (Smartt+, 2009)
J/ApJ/719/1784 : Yellow supergiants in the SMC (Neugent+, 2010)
J/AJ/142/103 : Cool evolved stars in SAGE-SMC and SAGE-LMC (Boyer+, 2011)
J/ApJ/750/97 : The yellow and red supergiants of M33 (Drout+, 2012)
J/A+A/537/A146 : Stellar models with rotation. Z=0.014 (Ekstrom+, 2012)
J/ApJ/749/177 : Yellow and red supergiants in the LMC (Neugent+, 2012)
J/ApJ/758/133 : Metallicity profile of M31 HII regions & PNe (Sanders+, 2012)
J/A+A/558/A103 : Stellar models with rotation. Z=0.002 (Georgy+, 2013)
J/ApJ/826/224 : RSG and foreground candidates in M31 (Massey+, 2016)
J/MNRAS/478/3138 : Cool supergiants in Magellanic Clouds (Davies+, 2018)
J/A+A/616/A12 : Gaia DR2 sources in GC and dSph (Gaia Collaboration+, 2018)
J/A+A/629/A91 : A source catalog for the SMC (Yang+, 2019)
Byte-by-byte Description of file: table[23].dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Field Field A, B or C=control field;
column added by CDS
3- 4 I2 h RAh [0] Hour of Right Ascension (J2000)
6- 7 I2 min RAm [33/48] Minute of Right Ascension (J2000)
9- 13 F5.2 s RAs Second of Right Ascension (J2000)
15 A1 --- DE- [+] Sign of the Declination (J2000)
16- 17 I2 deg DEd [40/42] Degree of Declination (J2000)
19- 20 I2 arcmin DEm Arcminute of Declination (J2000)
22- 25 F4.1 arcsec DEs Arcsecond of Declination (J2000)
27- 32 F6.3 mag Jmag [6.3/20.5] Apparent J band magnitude (1)
34- 38 F5.3 mag e_Jmag [0.001/0.4] The 1σ uncertainty in Jmag
40- 45 F6.3 mag Ksmag [5.3/18.5] Apparent Ks band magnitude (1)
47- 51 F5.3 mag e_Ksmag [0.001/0.3] The 1σ uncertainty in Ksmag
53- 57 F5.3 mag J-Ks [0.5/2] The (J-Ks) color index
59- 63 F5.3 mag e_J-Ks [0.001/0.4] The 1σ uncertainty in J-Ks
65 I1 --- Mm [0/3]? Membership flag (2)
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Note (1): For the brightest stars (Jmag≲12 or Ksmag≲12), magnitudes are taken
from the 2MASS catalog. See Section 3.
Note (2): Based upon our analysis of the Gaia DR2 results. Code as follows:
0 = member (1484 occurrences for M31 fields A & B, 232 for control field);
1 = uncertain;
2 = non-member;
3 = no Gaia data available.
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History:
From electronic version of the journal
(End) Prepared by [AAS], Emmanuelle Perret [CDS] 12-Jul-2021