J/ApJ/821/54 XMM spectral analysis of Draco dSph (Sonbas+, 2016) ================================================================================ X-ray sources in the dwarf spheroidal galaxy Draco. Sonbas E., Rangelov B., Kargaltsev O., Dhuga K.S., Hare J., Volkov I. =2016ApJ...821...54S (SIMBAD/NED BibCode) ================================================================================ ADC_Keywords: X-ray sources ; Active gal. nuclei ; Photometry, SDSS ; Photometry, infrared Keywords: dark matter; galaxies: dwarf; galaxies: individual: Draco dwarf; novae, cataclysmic variables; stars: carbon; X-rays: binaries Abstract: We present the spectral analysis of an 87ks XMM-Newton observation of Draco, a nearby dwarf spheroidal galaxy. Of the approximately 35 robust X-ray source detections, we focus our attention on the brightest of these sources, for which we report X-ray and multiwavelength parameters. While most of the sources exhibit properties consistent with active galactic nuclei, few of them possess the characteristics of low-mass X-ray binaries (LMXBs) and cataclysmic variable (CVs). Our analysis places constraints on the population of X-ray sources with LX>3x10^33^erg/s in Draco, suggesting that there are no actively accreting black hole and neutron star binaries. However, we find four sources that could be quiescent state LMXBs/CVs associated with Draco. We also place constraints on the central black hole luminosity and on a dark matter decay signal around 3.5keV. Description: The 87ks image of Draco (Figure 1; RA=17:20:12.4 and DEC=+57:54:55.3 (J2000)) was obtained by the European Space Agency's (ESA) X-ray Multi-Mirror Mission-Newton (XMM-Newton) between 2009 August 4 and 28 (PI: K. Dhuga). We used the 3XMM-DR54 (3XMM) catalog (Rosen et al. 2015, IX/46) for the automated multiwavelength (MW) classification described in Section 3.1. The parameters obtained from the 3XMM catalog are the source coordinates and X-ray fluxes in four different energy bands. The Hubble Space Telescope (HST) partly observed Draco with the WFPC2, ACS/WFC, and WFC3/UVIS cameras between 2001 Aug 18 and 2013 Oct 14. Objects: ------------------------------------------------------------- RA (ICRS) DE Designation(s) ------------------------------------------------------------- 17 20 12.4 +57 54 55.3 Draco = NAME DRACO Dwarf Galaxy ------------------------------------------------------------- File Summary: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- ReadMe 80 . This file table3.dat 150 35 Properties and automated results for classification X-ray sources in the Draco field -------------------------------------------------------------------------------- See also: B/xmm : XMM-Newton Obs. Log (XMM-Newton Science Operation Center, 2012) IX/46 : XMM-Newton Serendipitous Source Catalogue 3XMM-DR5 (XMM-SSC, 2016) II/328 : AllWISE Data Release (Cutri+ 2013) V/139 : The SDSS Photometric Catalog, Release 9 (Adelman-McCarthy+, 2012) VII/258 : Quasars and Active Galactic Nuclei (13th Ed.) (Veron+ 2010) V/136 : Teff and metallicities for Tycho-2 stars (Ammons+, 2006) V/123 : Catalog of Cataclysmic Variables (Downes+ 2001-2006) II/246 : 2MASS All-Sky Catalog of Point Sources (Cutri+ 2003) J/ApJ/813/28 : Autoclassification of the variable 3XMM sources (Farrell+, 2015) J/MNRAS/451/2735 : Four close dSph XXM observations (Manni+, 2015) J/MNRAS/448/2717 : Resolved stellar spectra Bayesian analysis (Walker+, 2015) J/AJ/149/42 : Proper motion of Draco dwarf galaxy from HST (Pryor+, 2015) J/ApJ/756/27 : Classif. of sources from the 2XMMi-DR3 cat. (Lin+, 2012) J/A+A/469/807 : Catalogue of Galactic low-mass X-ray binaries (Liu+, 2007) J/MNRAS/375/831 : Draco MegaCam, INT and HST photometry (Segall+, 2007) J/A+A/455/1165 : Catalogue of Galactic high-mass X-ray binaries (Liu+, 2006) J/A+A/442/165 : IJKs photom. of late-type stars in Draco dSph (Cioni+, 2005) J/ApJS/160/319 : COUP: observations and source lists (Getman+, 2005) J/ApJS/145/245 : SDSS stars in Draco dwarf spheroidal galaxy (Rave+, 2003) Byte-by-byte Description of file: table3.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 2 I2 --- Seq Sequential Running number 4- 11 F8.4 deg RAdeg Right Ascension, decimal degrees (J2000) 13- 19 F7.4 deg DEdeg Declination, decimal degrees (J2000) 21- 24 F4.2 arcsec ePos [0.4/6.3] Positional Uncertainty from 3XMM-DR5 catalog 26- 30 F5.1 10-14mW/m2 Flux [0.1/157] Observed X-ray flux in the 0.5-12keV range 32- 36 F5.2 10-14mW/m2 e_Flux [0.3/16] Uncertainty in Flux 38- 42 F5.2 --- HR2 Hardness ratio (1) 44- 47 F4.2 --- e_HR2 [0.01/0.4] Uncertainty in HR2 49- 53 F5.2 --- HR4 Hardness ratio (1) 55- 58 F4.2 --- e_HR4 [0.01/0.9] Uncertainty in HR4 60- 64 F5.1 --- S/N [6/116] Signal-to-noise ratio 66- 70 F5.2 mag umag [10/29.2]? SDSS DR9 u magnitude 72- 76 F5.2 mag gmag [11.3/23.2]? SDSS DR9 g magnitude 78- 82 F5.2 mag rmag [11.4/22.5]? SDSS DR9 r magnitude 84- 88 F5.2 mag imag [11.3/23.2]? SDSS DR9 i magnitude 90- 94 F5.2 mag zmag [9.8/22.5]? SDSS DR9 z magnitude 96-100 F5.2 mag Jmag [7.7/16.7]? 2MASS J magnitude 102-106 F5.2 mag Hmag [7.4/16.5]? 2MASS H magnitude 108-112 F5.2 mag Ksmag [7.4/15.8]? 2MASS Ks magnitude 114-118 F5.2 mag W1mag [7.7/16.2]? WISE W1 magnitude (3.35um) 120-124 F5.2 mag W2mag [7.4/16.4]? WISE W2 magnitude (4.6um) 126-130 F5.2 mag W3mag [7.3/13]? WISE W3 magnitude (11.6um) 132-141 A10 --- Class Class 143-144 I2 --- Prob [84/99]? Probability for not being a spurious detection (see section 3.2) 146-150 A5 --- Flag Object Flags (2) -------------------------------------------------------------------------------- Note (1): HR2=(F_1.2-2_-F_0.2-1.2_)/(F_1.2-2_+F_0.2-1.2_) and HR4=(F_2-7_-F_0.5-2_)/(F_2-7_+F_0.5-2_), where F_X-Y_ is the observed flux in the X-Y keV energy band, e.g., 1.2-2keV band. Note (2): Object Flags as follows: h = GM Dra, variable star in Tycho 2 (Hog et al. 2000, Cat. I/259) i = A cool K9 type star with X-ray luminosity of 3.7x10^29erg/s at a distance of ~125pc; Ammons et al. 2006, Cat. V/136. j = Visually resolved in the SDSS images. k = Symbiotic star in Draco, Belczynski et al. 2000, J/A+AS/146/407. l = Source 30 also shows complex morphology (likely, superposition of star and galaxy as can be seen in Figure~2. m = Three sources have the uncertainties of fluxes in the individual bands (1-2keV, 2-4.5keV, etc.) larger than the fluxes themselves, according to 3XMM-DR5, which results in the large total flux uncertainty. n = In these cases the uncertainty is strongly asymmetric, because the value of HR hits the boundary; the maximum uncertainty is given in this table. -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Prepared by [AAS], Emmanuelle Perret [CDS] 23-Jun-2016