J/MNRAS/440/365 Galactic Bulge accreting binaries spectroscopy (Torres+, 2014)
Identification of 23 accreting binaries in the Galactic Bulge Survey.
Torres M.A.P., Jonker P.G., Britt C.T., Johnson C.B., Hynes R.I.,
Greiss S., Steeghs D., Maccarone T.J., Ozel F., Bassa C., Nelemans G.
<Mon. Not. R. Astron. Soc., 440, 365-386 (2014)>
=2014MNRAS.440..365T 2014MNRAS.440..365T
ADC_Keywords: Binaries, X-ray ; Accretion ; Radial velocities ;
Equivalent widths
Keywords: accretion, accretion discs - black hole physics -
techniques: radial velocities - binaries: close - stars: neutron -
X-rays: binaries
Abstract:
We present the identification of optical counterparts to 23 GBS X-ray
sources. All sources are classified as accreting binaries according to
the emission-line characteristics inferred from medium-resolution
spectroscopy. To distinguish accreting binaries from chromospherically
active objects, we develop criteria based on Hα and HeI
λλ5786, 6678 emission-line properties available in the
literature. The spectroscopic properties and photometric variability
of each object is discussed and a classification is given where
possible. At least 12 of the 23 systems show an accretion-dominated
optical spectrum and another 6 show stellar absorption features in
addition to emission lines indicating that they are probably accreting
binaries in quiescence or in a low accretion rate state. Two sources
are confirmed to be eclipsing: CX207 and CX794. CX207 is likely a
magnetic cataclysmic variable (CV), while CX794 is a nova-like CV in
the period gap. Finally, the large broadening (2100km/s FWHM) of the
Hα emission lines in CX446 and CX1004 suggests that they are
also high-inclination or even eclipsing systems. Whether the compact
object is a white dwarf in an eclipsing CV, a neutron star or a black
hole in a high-inclination low-mass X-ray binary remains to be
established.
Description:
The spectroscopic observations were obtained in service mode under
programmes 085.D-0441(A) and 087.D-0596(A).
One hour observing blocks (OBs) were executed per pointing, consisting
of acquisition imaging, two spectroscopic integrations of 875s, three
flat-field exposures and a helium-argon lamp exposure for wavelength
calibration. The standard data reduction steps were performed with the
ESO-VIMOS pipeline
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 84 27 Source position and log of the VIMOS and
Mosaic-II observations
table2.dat 92 95 Spectroscopic measurements
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See also:
J/ApJ/761/162 : Tycho-2 stars in Galactic Bulge Survey (Hynes+, 2012)
J/ApJS/194/18 : The Galactic Bulge Survey: X-ray observations (Jonker+, 2011)
J/ApJS/210/18 : X-ray survey of the Galactic Bulge (CXOGBS) (Jonker+, 2014)
Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq [1/23] Sequential number
4- 9 A6 --- GBS GBS name (CXNNNN)
11- 19 F9.5 deg RAdeg Right ascension (J2000)
21- 30 F10.6 deg DEdeg Declination (J2000)
32- 37 I6 --- ObsIDs ?=- VIMOS OB ID (spectroscopy)
39- 44 I6 --- ObsIDp ?=- VIMOS OB ID (pre-imaging)
46 I1 --- Q [1/4]? VIMOS Quadrant
48- 57 A10 "date" Date Observation date
59- 60 I2 --- Nf [4/38]? Number of Mosaic-II frames
62- 67 A6 --- --- [CXOGBS]
69- 84 A16 --- CXOGBS CXOGBS name (JHHMMSS.s+DDMMSS)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- GBS GBS name (CXNNNN)
7 A1 --- f_GBS [*] light contamination (1)
8- 33 A26 --- n_GBS Note
35- 38 I4 0.1nm lambda [4686/9546] Line wavelength (Å)
40- 49 A10 --- Line line identification
51 I1 --- Nobs [1/2]? First or second observation
53- 58 F6.1 km/s RV ?=- Radial velocity
60- 64 F5.1 km/s e_RV ? rms uncertainty on RV
66- 67 A2 --- l_EW [~> ] Limit flag on EW
68- 73 F6.2 0.1nm EW ?=- Equivalent width
75- 79 F5.2 0.1nm e_EW ? rms uncertainty on EW
81- 82 A2 --- l_FWHM [~> ] Limit flag on FWHM
83- 87 F5.2 0.1nm FWHM ?=- Line FWHM
89- 92 F4.2 0.1nm e_FWHM ? rms uncertainty on FWHM
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Note (1): An * indicates that the measured EW is most likely a lower limit due
to contamination of unresolved star/s during the extraction of the spectra.
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 16-Jan-2015