J/ApJ/844/40 Variable stars in M31 and M33. V. HR diagram (Humphreys+, 2017)
Luminous and variable stars in M31 and M33.
V. The upper HR diagram.
Humphreys R.M., Davidson K., Hahn D., Martin J.C., Weis K.
<Astrophys. J., 844, 40-40 (2017)>
=2017ApJ...844...40H 2017ApJ...844...40H (SIMBAD/NED BibCode)
ADC_Keywords: Stars, variable ; Stars, giant ; Extinction ;
Magnitudes, absolute ; Galaxies, nearby
Keywords: galaxies: individual: (M31, M33); stars: massive; supergiants
Abstract:
We present HR diagrams for the massive star populations in M31 and
M33, including several different types of emission-line stars: the
confirmed luminous blue variables (LBVs), candidate LBVs, B[e]
supergiants, and the warm hypergiants. We estimate their apparent
temperatures and luminosities for comparison with their respective
massive star populations and evaluate the possible relationships of
these different classes of evolved, massive stars, and their
evolutionary state. Several of the LBV candidates lie near the LBV/S
Dor instability strip that supports their classification. Most of the
B[e] supergiants, however, are less luminous than the LBVs. Many are
very dusty with the infrared flux contributing one-third or more to
their total flux. They are also relatively isolated from other
luminous OB stars. Overall, their spatial distribution suggests a more
evolved state. Some may be post-RSGs (red supergiants) like the warm
hypergiants, and there may be more than one path to becoming a B[e]
star. There are sufficient differences in the spectra, luminosities,
spatial distribution, and the presence or lack of dust between the
LBVs and B[e] supergiants to conclude that one group does not evolve
into the other.
Description:
We use the large data set published by Massey+ (2016, J/AJ/152/62),
together with our own spectral classifications from Papers II
(Humphreys+, 2014, J/ApJ/790/48; III (Gordon+, 2016, J/ApJ/825/50),
and IV (Humphreys+, 2017, J/ApJ/836/64), to create a catalog of
luminous O-, B-, and A-type stars representative of the hot star
populations in M31 and M33.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 103 33 Extinction, luminosities, and temperatures
-- luminous blue variables (LBVs) and
candidates
table3.dat 98 27 Extinction, luminosities, and temperatures
-- B[e] supergiants and warm hypergiants
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See also:
J/ApJ/469/355 : Teff, B-V and BC relation (Flower, 1996)
J/ApJ/469/629 : UV-brightest stars of M33 and its nucleus (Massey+ 1996)
J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)
J/ApJ/690/837 : CN and CO observations toward AGB stars (Milam+, 2009)
J/MNRAS/395/1409 : Type II-P SN progenitor constraints (Smartt+, 2009)
J/A+A/522/A3 : M33 CO(2-1) and HI integrated intensity maps (Gratier+, 2010)
J/AJ/142/139 : A new catalog of HII regions in M31 (Azimlu+, 2011)
J/A+A/537/A146 : Stellar models with rotation. 0.8<M<120 (Ekstrom+, 2012)
J/ApJ/745/156 : M31 Cepheids with HST/WFC3 (Riess+, 2012)
J/ApJ/790/48 : Variable stars in M31 & M33. II. LBVs (Humphreys+, 2014)
J/ApJ/795/170 : Sample SNRs for M31 and M33 (Jennings+, 2014)
J/ApJ/825/50 : Variable stars in M31 & M33. III. YSGs & RSGs (Gordon+, 2016)
J/AJ/152/62 : Revised LGGS UBVRI photom. of M31 & M33 stars (Massey+, 2016)
J/A+A/601/A76 : DIRECT LCs of 21 luminous YSGs in M33 (Kourniotis+, 2017)
J/ApJ/836/64 : Luminous variable stars in M31 & M33. IV. (Humphreys+, 2017)
http://etacar.umn.edu/LuminousStars/M31M33/ : M31 & M33 HST Treasury Program
Byte-by-byte Description of file: table[23].dat
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Bytes Format Units Label Explanations
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1- 3 A3 --- Gal Galaxy name (M33 or M31)
5- 8 A4 --- Var Variable type (1)
10- 28 A19 --- Star Star designation
30- 32 A3 --- f_Star Flag(s) on Star (2)
34- 37 F4.2 mag AvS1 [0.3/2.4]? Extinction (or lower range)
from neighboring stars method
38 A1 --- --- [-]
39- 41 F3.1 mag AvS2 [0.9]? Upper range of AvS1
43 I1 --- o_AvS1 ? Number of nearby stars used
44 A1 --- u_AvS1 Uncertainty flag on AvS
46- 49 F4.2 mag AvHI [0.3/2.1]? Extinction from NHI method
51- 54 F4.2 mag Av [0.3/2.4]? Adopted extinction
55 A1 --- u_Av Uncertainty flag on Av
57- 61 F5.1 mag VMag [-10.2/-5.3]? Extinction-corrected absolute
visual magnitude
62 A1 --- u_VMag [:v] VMag uncertainty flag (:) or var flag (v)
64- 68 I5 K Temp1 [5000/42000]? Temperature (or upper range)
69 A1 --- u_Temp1 [:-] Uncertainty flag (or range flag) on Temp1
70- 74 I5 K Temp2 ? Lower range of Temperature
76- 81 F6.2 mag Mbol1 [-12.6/-6.2]? Bolometric magnitude
(or lower range)
82 A1 --- u_Mbol1 [:] Uncertainty flag on Mbol1
83- 87 F5.1 mag Mbol2 ? Upper range of Bolometric magnitude
89-103 A15 --- Group Stellar group (3)
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Note (1): Variable type as follows:
LBV = Luminous blue variable (9 occurrences)
LBVc = Luminous blue variable candidate (24 occurrences)
Be = B[e] supergiant (18 occurrences)
HG = Warm hypergiant (9 occurrences)
Note (2): Flag as follows:
b = Var A-1 and Var 15 have both shown spectroscopic and photometric
variability in the past few years (see Paper IV,
Humphreys+, 2017, J/ApJ/836/64). Their SEDs are uncertain.
c = New LBV in M31. See Humphreys+ (2015PASP..127..347H 2015PASP..127..347H).
Its quiescent or minimum light state is uncertain.
d = See Papers III and IV (Gordon+, 2016, J/ApJ/825/50 and
Humphreys+, 2017, J/ApJ/836/64) for an LBV candidate or post-RSG.
The adopted Av is from the observed colors. Av from the nearby stars
would yield Mv=-9.2, MBol=-9.5.
e = A probable low-luminosity LBV. See discussions in Papers II and IV
(Humphreys+, 2014, J/ApJ/790/48 and 2017, J/ApJ/836/64).
f = Var C is in eruption. See Humphreys+ (2014ApJ...782L..21H 2014ApJ...782L..21H).
g = UIT 008 (J013245.41+303858.3). See Papers II and IV
(Humphreys+, 2014, J/ApJ/790/48 and 2017, J/ApJ/836/64).
h = M33C-4640 may be a post-RSG star, not an LBV candidate (Paper II,
Humphreys+, 2014, J/ApJ/790/48), but it has weak FeII emission.
i = UIT 301, B416. This very luminous hot supergiant is very likely more
than one star as discussed in Paper II (Humphreys+, 2014, J/ApJ/790/48).
It is listed as an LBV candidate because of the [FeII] and
FeII emission in its spectrum.
j = Romano's star, see the discussion in Paper II (Humphreys+,
2014, J/ApJ/790/48).
k = Circumstellar dust.
l = Var A is optically obscured. See Humphreys+ (1987AJ.....94..315H 1987AJ.....94..315H,
2006AJ....131.2105H 2006AJ....131.2105H) for a discussion of its light curve, spectrum, and
energy distribution.
m = B324 is possibly the most visually luminous star in M33.
See Paper II (Humphreys+, 2014, J/ApJ/790/48) for a discussion of its
spectrum and SED. B324 is probably not a post-RSG, but more likely
evolving to cooler temperatures.
n = N is the designator from the Valeev+ (2010AstBu..65..140V 2010AstBu..65..140V) survey used
in Papers I and II (Humphreys+, 2013ApJ...773...46H 2013ApJ...773...46H and
2014, J/ApJ/790/48). In Papers III and IV (Gordon+, 2016, J/ApJ/825/50
and Humphreys+, 2017, J/ApJ/836/64) we used a V followed by the number.
o = See Kourniotis+ (2017, J/A+A/601/A76).
Note (3): References: Hodge (1981aag..book.....H 1981aag..book.....H),
Humphreys & Sandage (1980ApJS...44..319H 1980ApJS...44..319H).
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History:
From electronic version of the journal
Acknowledgements:
Roberta Humphreys [Minnesota Institute for Astrophysics] who provided
the coordinates for 5 objects not included in Papers II or IV.
References:
Humphreys et al. Paper I. 2013ApJ...773...46H 2013ApJ...773...46H
Humphreys et al. Paper II. 2014ApJ...790...48H 2014ApJ...790...48H Cat. J/ApJ/790/48
Gordon et al. Paper III. 2016ApJ...825...50G 2016ApJ...825...50G Cat. J/ApJ/825/50
Humphreys et al. Paper IV. 2017ApJ...836...64H 2017ApJ...836...64H Cat. J/ApJ/836/64
Humphreys et al. Paper V. 2017ApJ...844...40H 2017ApJ...844...40H This catalog
(End) Emmanuelle Perret [CDS] 15-Sep-2017