J/A+A/562/A24 Cool carbon stars in the halo and Fornax dSph (Mauron+, 2014)
Cool carbon stars in the halo and in dwarf galaxies: Hα, colours, and
variability.
Mauron N., Gigoyan K.S., Berlioz-Arthaud P., Klotz A.
<Astron. Astrophys., 562, A24 (2014)>
=2014A&A...562A..24M 2014A&A...562A..24M
ADC_Keywords: Stars, variable ; Stars, halo ; Photometry, infrared ;
Stars, giant ; Photometry, RI ; Galactic plane ; Galaxies, nearby
Keywords: stars: carbon - Galaxy: halo - Galaxy: stellar content
Abstract:
The population of cool carbon (C) stars located far from the galactic
plane is probably made of debris of small galaxies such as the
Sagittarius dwarf spheroidal galaxy (Sgr), which are disrupted by the
gravitational field of the Galaxy. We aim to know this population
better through spectroscopy, 2MASS photometric colours, and
variability data. When possible, we compared the halo results to C
star populations in the Fornax dwarf spheroidal galaxy, Sgr, and the
solar neighbourhood. We first present a few new discoveries of C stars
in the halo and in Fornax. The number of spectra of halo C stars is
now 125. Forty percent show Hα in emission. The narrow location
in the JHK diagram of the halo C stars is found to differ from that of
similar C stars in the above galaxies. The light curves of the
Catalina and LINEAR variability databases were exploited to derive the
pulsation periods of 66 halo C stars. A few supplementary periods were
obtained with the TAROT telescopes. We confirm that the period
distribution of the halo strongly resembles that of Fornax, and we
found that it is very different from the C stars in the solar
neighbourhood. There is a larger proportion of short-period Mira/SRa
variables in the halo than in Sgr, but the survey for C stars in this
dwarf galaxy is not complete, and the study of their variability needs
to be continued to investigate the link between Sgr and the cool halo
C stars.
Description:
Spectroscopy of halo candidate C stars was achieved at ESO (La Silla)
on 17-18 October 2009 at the NTT telescope equipped with the EFOSC2
instrument in the spectral range 5200-9300Å. We were able to secure
the spectra of 25 candidates with exposure times of generally a few
minutes, and eventually, eight were found to be C-rich. We also
observed three carbon stars in the Carina dwarf galaxy because they
were erroneously believed to be in the halo, and for comparison APM
2225-1401, a C star from the list of Totten and Irwin
(1998MNRAS.294....1T 1998MNRAS.294....1T).
We found spectra that covered the Hα region for four halo stars
in the Byurakan Astrophysical Observatory archive. They were obtained
with the BAO 2.6m telescope and the ByuFOSC2 spectrograph. These
spectra were taken on 28 March 1999, 12 June 2002, 11 May 2000, and 11
June 2000 with a resolution ∼8Å.
Concerning Fornax, spectra of C stars were found in the ESO Archive
(program 70.D-0203, P.I. Marc Azzopardi). They were obtained on 5
November 2002 with the ESO 3.6m telescope and the EFOSC instrument
with a resolution ∼23Å and a spectral coverage from 4000Å to
7950Å.
Sixteen C stars were monitored with the ground-based 25cm diameter
TAROT telescopes. This monitoring took place irregularly at ESO La
Silla and Observatoire de la Cote d'Azur (France) beginning in 2010.
Thanks to the recently released Catalina and LINEAR databases, we were
able to examine the light curves of 143 halo C stars and found 66 new
periodic (Mira or SRa-type) variables among them.
File Summary:
--------------------------------------------------------------------------------
FileName Lrecl Records Explanations
--------------------------------------------------------------------------------
ReadMe 80 . This file
table1.dat 92 23 Observed carbon stars in the halo and in the
dwarf galaxies Carina and Fornax
table2.dat 55 16 TAROT observations of cool carbon stars and
obtained periods
table5.dat 42 22 Fornax C stars with periods
tablea2.dat 49 39 Objects in the direction of Fornax that are not
carbon stars
tablea4.dat 85 66 Halo C stars with periods
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See also:
II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003)
I/284 : The USNO-B1.0 Catalog (Monet+ 2003)
I/252 : The USNO-A2.0 Catalogue (Monet+ 1998)
J/MNRAS/427/2647 : Sgr dSph stars spectral classification (McDonald+, 2012)
J/A+A/513/A62 : Sgr dSph VIMOS phot. and RVs (Giuffrida+, 2010)
J/A+A/523/A17 : Individual stars in Fornax dSph center (Letarte+, 2010)
J/ApJ/696/870 : Catalina Real-time Transient Survey (CRTS) (Drake+, 2009)
J/MNRAS/394/795 : AGB stars in Fornax dSph galaxy (Whitelock+, 2009)
J/ApJ/696/870 : Catalina Real-time Transient Survey (CRTS) (Drake+, 2009)
J/AJ/136/1290 : Ultracool dwarfs from the 2MASS (Reid+, 2008)
J/A+A/467/1025 : JHK photometry of Fornax RGB (Gullieuszik+, 2007)
J/AJ/133/1470 : TAROT suspected variable star catalog (Damerdji+, 2007)
J/AJ/133/439 : Luminosity function of M7-L8 ultracool dwarfs (Cruz+, 2007)
J/ApJ/658/367 : Abundances of carbon stars in Galactic halo (Komiya+, 2007)
J/MNRAS/369/751 : Near-infrared photometry of carbon stars (Whitelock+, 2006)
J/AJ/126/2421 : 2MASS-Selected sample of ultracool dwarfs (Cruz+, 2003)
J/A+A/369/932 : RI photometry of LMC carbon stars (Kontizas+, 2001)
J/A+AS/113/539 : A survey of carbon stars in the SMC (Morgan+, 1995)
J/A+AS/97/603 : C stars in SMC (Rebeirot+ 1993)
J/ApJS/66/387 : Case low-dispersion Survey VII. (Sanduleak+ 1988)
http://nesssi.cacr.caltech.edu/DataRelease/ : The Catalina Surveys DR2 page
https://astroweb.lanl.gov/lineardb/ : The LINEAR Survey photometric database
Byte-by-byte Description of file: table1.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 3 A3 --- Gal Galaxy identification (1)
5- 7 A3 --- ID Star identifier (if any) (2)
9- 13 A5 --- --- [2MASS]
15- 33 A19 --- 2M 2MASS identifier (JHHMMSS.ss+DDMMSS.s)
35- 41 F7.3 deg GLON Galactic longitude
43- 49 F7.3 deg GLAT Galactic latitude
51- 54 F4.1 mag Bmag [14.9/23.3] B-band magnitude (3)
56- 59 F4.1 mag Rmag [11.1/19] R-band magnitude (3)
61- 63 F3.1 mag B-R [1.7/7.3] B-R color index (3)
65- 70 F6.3 mag Jmag [8.7/16.5] 2MASS J-band magnitude (4)
72- 77 F6.3 mag Hmag [7.8/15.2] 2MASS H-band magnitude (4)
79- 84 F6.3 mag Ksmag [7.3/14.5] 2MASS Ks-band magnitude (4)
86- 90 F5.3 mag J-Ks [1/2.6] J-Ks color index
92 A1 --- Note Note on alternative identification(s) (5)
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Note (1): Code as follows:
Nh2 = New halo C stars found in 2MASS
OhB = Observed halo C stars from the Byurakan survey
OsC = Observed C stars in Carina
OsF = Observed C stars in Fornax
Note (2): For halo stars that were selected through their position in the
JHK two-colour diagram, the "ID" column gives the running number
following those of Mauron (2008A&A...482..151M 2008A&A...482..151M). For Fornax, this
column is an internal designation.
Note (3): B and R are generally taken from the USNO-A2 catalogue, with
1-σ uncertainties of 0.25mag; except for F29 and F36 that are
not available in USNO-A2.0 and were derived from Supercosmos (Hambly
et al. 2001MNRAS.326.1279H 2001MNRAS.326.1279H). Similarly, those of F31 and F58 were
derived from the USNO-B1.0 catalogue.
Note (4): The J,H,K data are near-infrared magnitudes from the 2MASS
catalogue, with uncertainties of 0.02 to 0.04mag.
Note (5): Note as follows:
1 = FBS 1339-070
2 = FBS 1516+151
3 = FBS 1615-048
4 = FBS 1618-087
5 = ALW Carina 2 (Azzopardi et al. 1986A&A...161..232A 1986A&A...161..232A)
6 = C3 of Mould et al. (1982ApJ...254..500M 1982ApJ...254..500M; <[MCA82] C3> in Simbad),
also ALW Carina 6
7 = C4 of Mould et al. (1982ApJ...254..500M 1982ApJ...254..500M; <[MCA82] C4> in Simbad),
also ALW Carina 7
n = New C star (see table 3)
k = Known C star (see table 3)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 13 A13 --- Name Star name
15 A1 --- n_Per [n] Other value of period from literature (1)
17- 35 A19 --- 2M 2MASS identifier (JHHMMSS.ss+DDMMSS.s)
37- 41 F5.2 mag Ksmag [4.52/10.57] 2MASS Ks-band magnitude (2)
43- 46 F4.2 mag J-K [1.31/3.91] J-Ks color index
48- 50 I3 d Per Period
51 A1 --- u_Per Uncertainty flag on Per
53- 55 I3 d Pcl [230/424]? Period derived from
Catalina/LINEAR databases
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Note (1):
n = For m16, Battinelli & Demers (2012A&A...544A..10B 2012A&A...544A..10B) found P=229days.
Note (2): K from 2MASS is indicated and is lower than 7.0 in five cases.
These stars are too bright to be considered as halo C star with our
criteria and are included here for completeness. These objects are
ignored in the remainder of the paper.
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Byte-by-byte Description of file: table5.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- ID Internal identifier (ForNN)
7- 25 A19 --- 2M 2MASS identifier (JHHMMSS.ss+DDMMSS.s)
27- 31 F5.2 mag Ksmag [12.12/14.16] 2MASS Ks-band magnitude
33- 36 F4.2 mag J-K [1.1/3.5] 2MASS J-Ks color index
38- 40 I3 d Per [171/634] Period
42 A1 --- n_Per Period from literature (1)
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Note (1):
W = Per is from Whitelock et al. (2009, Cat. J/MNRAS/394/795), otherwise
Per is from this work.
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Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- --- [2MASS]
7- 27 A21 --- 2M 2MASS identifier (JHHMMSS.sss+DDMMSS.ss)
29- 34 F6.3 mag Kmag [13.1/14.5] 2MASS Ks-band magnitude
36- 40 F5.3 mag J-K [0.9/2] 2MASS J-Ks color index
42- 45 F4.1 mag Rmag [15.6/17.2] USNO-A2 R-band magnitude
47- 49 F3.1 mag B-R [0/2.3] USNO-A2 B-R color index
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Byte-by-byte Description of file: tablea4.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 15 A15 --- Name Star name (1)
17- 21 A5 --- --- [2MASS]
23- 41 A19 --- 2M 2MASS identifier (JHHMMSS.ss+DDMMSS.s)
43- 49 F7.3 deg GLON Galactic longitude
51- 57 F7.3 deg GLAT Galactic latitude
59- 63 F5.2 mag Ksmag [7.07/14.5] 2MASS Ks-band magnitude
65- 68 F4.2 mag J-K [1.3/4.41] 2MASS J-Ks color index
70- 74 F5.1 d Per [147.6/515.6] Period
76- 78 F3.1 mag Amp [0.3/2.1] Catalina amplitude AC of the
fitted sinusoid
80- 83 A4 --- M/SR "Mira" class (semi-regular otherwise) (2)
85 A1 --- Note L: LINEAR data were used in addition to those
of Catalina
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Note (1): Periodic variables found with Catalina and LINEAR data: the objects
named "SDSS Green NNN" are taken from Table 1 of Green
(2013ApJ...765...12G 2013ApJ...765...12G). Similarly, the object named "2MASS Gizis 32" comes
from Table 1 of Gizis (2002ApJ...575..484G 2002ApJ...575..484G). The names "mNNN" come from the
lists in Papers I to IV (2004A&A...418...77M 2004A&A...418...77M, 2005A&A...438..867M 2005A&A...438..867M,
2007A&A...475..843M 2007A&A...475..843M and 2008A&A...482..151M 2008A&A...482..151M, respectively).
Note (2): Mira is indicated in the M/SR column when AC>1.5mag.
We consider all others as SRa type variables.
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History:
From electronic version of the journal
References:
Mauron et al. Paper I. 2004A&A...418...77M 2004A&A...418...77M
Mauron et al. Paper II. 2005A&A...438..867M 2005A&A...438..867M
Mauron et al. Paper III. 2007A&A...475..843M 2007A&A...475..843M
Mauron, N. Paper IV. 2008A&A...482..151M 2008A&A...482..151M
(End) Emmanuelle Perret [CDS] 27-Mar-2014