J/AJ/152/62 Revised LGGS UBVRI photometry of M31 and M33 stars (Massey+, 2016)
A spectroscopic survey of massive stars in M31 and M33.
Massey P., Neugent K.F., Smart B.M.
<Astron. J., 152, 62 (2016)>
=2016AJ....152...62M 2016AJ....152...62M (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, nearby ; Stars, nearby ; Stars, luminous ;
Photometry, UBVRI ; Spectral types
Keywords: catalogs - galaxies: individual (M31, M33) -
galaxies: stellar content - Local Group - stars: early-type
Abstract:
We describe our spectroscopic follow-up to the Local Group Galaxy
Survey (LGGS) photometry of M31 and M33. We have obtained new
spectroscopy of 1895 stars, allowing us to classify 1496 of them for
the first time. Our study has identified many foreground stars, and
established membership for hundreds of early- and mid-type
supergiants. We have also found nine new candidate luminous blue
variables and a previously unrecognized Wolf-Rayet star. We republish
the LGGS M31 and M33 catalogs with improved coordinates, and including
spectroscopy from the literature and our new results. The spectroscopy
in this paper is responsible for the vast majority of the stellar
classifications in these two nearby spiral neighbors. The most
luminous (and hence massive) of the stars in our sample are early-type
B supergiants, as expected; the more massive O stars are more rare and
fainter visually, and thus mostly remain unobserved so far. The
majority of the unevolved stars in our sample are in the 20-40M☉
range.
Description:
The Local Group Galaxy Survey (LGGS) provides UBVRI plus
interference-image photometry of luminous stars in the spiral galaxies
M31 and M33, along with those found in seven dwarf systems currently
forming massive stars (IC 10, NGC 6822, WLM, Sextans A and B, Pegasus,
and Phoenix) with the intent of serving as a starting point for
systematic exploration of the stellar content of our nearest neighbors
beyond the Magellanic Clouds (MCs; Massey et al. 2006, Cat.
J/AJ/131/2478; Massey ey al. 2007, Cat. J/AJ/134/2474; Massey et al.
2007, Cat. J/AJ/133/2393; Massey et al. 2011AJ....141...28M 2011AJ....141...28M).
All of the observations on which our new spectroscopy is based come
from the 6.5m MMT telescope used with the 300 fiber positioner
Hectospec. This instrument provides a 1° field-of-view, with a
choice of two gratings: (1) a 270 line/mm blazed at 5000Å, which
covers the entire visible region (3650-9200Å) at once with a
resolution of ∼5Å, and (2) a 600 line/mm grating blazed 6000Å,
which covers 2300Å at one time at a resolution of ∼2Å. The
fibers have a diameter of 1.5''. The majority of the new observations
reported here were obtained with the higher dispersion grating
nominally centered at 4800Å but actually covering 3700-6000Å.
Some additional new spectral types are those of the Wolf-Rayet stars
(non-WRs) found by Neugent & Massey 2011 (Cat. J/ApJ/733/123) and
Neugent et al. 2012 (Cat. J/ApJ/759/11); these data were obtained with
the lower-dispersion grating, with details reported in that paper.
The first year of observations were obtained during the Fall of 2009,
with nominally three nights assigned (2009B-0149), but poor weather
during the semester meant we obtained only four fields in M31 and one
field in M33. Each observation consisted of 3*45 minute exposures. The
second year (Fall 2010), two nights were nominally assigned (NOAO
2010B-0260), allowing us to observe three additional fields in M33,
two with 3*45 minute exposures and one with 3*40 minute exposures.
We list all of the known or suspected Luminous Blue Variables (LBVs)
in M31 and M33 in Tables 3 and 4. In Tables 5 and 6, we provide the
revised versions of the LGGS UBVRI catalogs of stars in M31 and M33.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table3.dat 88 25 M31 candidate luminous blue variables (cLBVs)
table4.dat 88 32 M33 candidate luminous blue variables (cLBVs)
table5.dat 160 371781 Updated M31 Local Group Galaxy Survey (LGGS) catalog
table6.dat 160 146620 Updated M33 Local Group Galaxy Survey (LGGS) catalog
refs.dat 69 37 References
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See also:
J/ApJ/759/11 : Wolf-Rayet content of M31 (Neugent+, 2012)
J/ApJ/750/97 : The yellow and red supergiants of M33 (Drout+, 2012)
J/ApJ/733/123 : The Wolf-Rayet content of M33 (NGC 598) (Neugent+, 2011)
J/ApJ/703/441 : Yellow supergiants in M31 (Drout+, 2009)
J/ApJ/703/420 : Red supergiants in M31 (Massey+, 2009)
J/AJ/134/2474 : Hα emission-line stars in 7 galaxies (Massey+, 2007)
J/AJ/133/2393 : UBVRI phot. in 7 Local Group dwarfs galaxies (Massey+, 2007)
J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)
J/ApJ/505/793 : New WR star in M33 (Massey+, 1998)
J/ApJ/501/153 : VRB photometry of red supergiants (Massey 1998)
J/ApJ/469/629 : UV-brightest stars of M33 and its nucleus (Massey+ 1996)
J/AJ/110/2715 : UBV photometry in NGC 6822, M31 and M33 (Massey+ 1995)
J/AJ/96/1884 : BVRJHK photometry of M31 red supergiants (Humphreys+ 1988)
http://tdc-www.harvard.edu/ : SAO Telescope Data Center
Byte-by-byte Description of file: table[34].dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- LGGS Star designation in the Local Group Galaxy
Survey (LGGS) (JHHMMSS.ss+DDMMSS.s format)
21- 26 F6.3 mag Vmag [14.8/20.4] The V-band magnitude
28- 33 F6.3 mag B-V [-0.13/0.99] The B-V color index
35- 40 F6.3 mag U-B [-1.24/-0.08] The U-B color index
42- 47 F6.3 mag V-R [-0.06/1.19] The V-R color index
49- 54 F6.3 mag R-I [-0.51/0.77]?=99.999 The R-I color index
56 A1 --- Cwd Index indicating the degree of crowding
(I<5%, C=20-80%, or X>80%) (G1)
58- 61 A4 --- r_Class References for spectral classification (1)
63- 74 A12 --- Class Spectral type classification (mostly cLBV)
76 A1 --- pRSG [1] 1=Considered as a "post Red SuperGiant (RSG)
warm hypergiant" by Humphreys et al.
2015PASP..127..347H 2015PASP..127..347H
78- 88 A11 --- XID Cross-identification
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Note (1): References for classification defined as follows:
1 = Current paper;
2 = Massey et al. 2006 (Cat. J/AJ/131/2478);
3 = Neugent et al. 2012 (Cat. J/ApJ/759/11);
4 = Massey et al. 2007a (Cat. J/AJ/134/2474);
5 = Hubble & Sandage 1953ApJ...118..353H 1953ApJ...118..353H, Humphreys 1975ApJ...200..426H 1975ApJ...200..426H;
6 = King et al. 1998ApJ...507..210K 1998ApJ...507..210K;
7 = Sandage & Tammann 1974ApJ...191..603S 1974ApJ...191..603S, Humphreys 1975ApJ...200..426H 1975ApJ...200..426H;
8 = Massey 2006ApJ...638L..93M 2006ApJ...638L..93M;
9 = Monteverde et al. 1996A&A...312...24M 1996A&A...312...24M;
10 = Massey et al. 1996 (Cat. J/ApJ/469/629);
11 = Clark et al. 2012A&A...541A.146C 2012A&A...541A.146C;
12 = Neugent & Massey 2011 (Cat. J/ApJ/733/123);
13 = Valeev et al. 2009MNRAS.396L..21V 2009MNRAS.396L..21V;
14 = Humphreys 1978ApJ...219..445H 1978ApJ...219..445H;
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Byte-by-byte Description of file: table[56].dat
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Bytes Format Units Label Explanations
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1- 20 A20 --- LGGS Star designation in the Local Group Galaxy Survey
(LGGS) (JHHMMSS.ss+DDMMSS.sA format)
22- 25 F4.2 --- Rgc [0/1.81] Galactocentric distance (Holmberg radii;
ρ) (1)
27- 28 I2 h RAh Hour of Right Ascension (J2000) (2)
30- 31 I2 min RAm Minute of Right Ascension (J2000) (2)
33- 37 F5.2 s RAs Second of Right Accension (J2000) (2)
39 A1 --- DE- Sign of the Declination (J2000) (2)
40- 41 I2 deg DEd Degree of Declination (J2000) (2)
43- 44 I2 arcmin DEm Minute of Declination (J2000) (2)
46- 49 F4.1 arcsec DEs Second of Declination (J2000) (2)
51- 56 F6.3 mag Vmag [12.5/24.5] The V-band magnitude
58- 63 F6.3 mag e_Vmag [0.003/0.55] The 1σ error in Vmag
65- 70 F6.3 mag B-V [-6.9/6.9] The B-V color index
72- 77 F6.3 mag e_B-V [0.003/0.78] The 1σ error in B-V
79- 84 F6.3 mag U-B [-7.1/7.7]?=99.999 The U-B color index
86- 91 F6.3 mag e_U-B [0.003/0.8]?=99.999 The 1σ error in U-B
93- 98 F6.3 mag V-R [-4.3/6.7] The V-R color index
100-105 F6.3 mag e_V-R [0.003/0.77] The 1σ error in V-R
107-112 F6.3 mag R-I [-5.2/5.8]?=99.999 The R-I color index
114-119 F6.3 mag e_R-I [0.003/0.62]?=99.999 The 1σ error in R-I
121-122 I2 --- NV [1/16] Number of V band measurements
124-125 I2 --- NB [1/20] Number of B band measurements
127-128 I2 --- NU [0/16] Number of U band measurements
130-131 I2 --- NR [1/16] Number of R band measurements
133-134 I2 --- NI [0/20] Number of I band measurements
136 A1 --- Cwd [CIKSX] Index for the degree of crowding
(I<5%, S=5-20%, C=20-80%, X>80%, or K) (G1)
138 I1 --- Mm [0/3]? Membership criterion based utpn spectroscopy
(1=member, 0=non-member, 2=possible member, or
3=unknown)
140-154 A15 --- SpT Spectral type
156-160 A5 --- r_SpT References for SpT; in refs.dat file
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Note (1): Deprojected distance within the plane of M31 in units of the Holmberg
radius. Assumes Holmberg radius of 95.3', inclination 77.0°, and a
position angle of the major axis of 35.0°. At a distance of 760kpc, a
Rgc value of 1.00 corresponds to 21.07kpc.
Note (2): We have slightly modified the coordinates to place them essentially on
the UCAC3/4 system (Zacharias et al. 2013, Cat. I/322); the original Local
Group Galaxy Survey (LGGS) coordinates were tied to the USNO-B1.0 catalog
(Monet et al. 2003, Cat. I/284 ), requiring small (∼0.3'') corrections to
place the stars on the same system as guide stars suitable for observing
with Hectospec. The result of these corrections is that the LGGS
designations no longer exactly correspond to the listed coordinates.
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Ref Reference code
4- 22 A19 --- BibCode Bibliographic code
24- 48 A25 --- Aut Authors names
50- 69 A20 --- Com Comment(s)
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Global Notes:
Note (G1):
Crowding, measured by the greatest contamination by neighbors in U, B, V,
R, or I with a 1.5arcsec slit in 1arc seeing:
I = Isolated (contamination<5%);
S = Somewhat isolated (5-20%);
C = Crowded (20-80%);
X = eXtremely crowded (>80%);
K = not explained in the text.
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History:
From electronic version of the journal
(End) Prepared by [AAS]; Sylvain Guehenneux [CDS] 26-Sep-2016