J/A+A/459/777 X-ray sources in Sagittarius and Carina dSph (Cignoni+, 2006)
A search for stellar X-ray sources in the Sagittarius and Carina dwarf galaxies. I. X-ray observations. Ramsay G., Wu K. <Astron. Astrophys., 459, 777-781 (2006)> =2006A&A...459..777R
ADC_Keywords: Galaxies, nearby ; X-ray sources Keywords: galaxies: dwarf - galaxies: individual: Sagittarius - galaxies: individual: Carina - X-rays: binaries - X-rays: galaxies Abstract: ROSAT observations found no convincing evidence for X-ray sources located in local dwarf spheroidal galaxies (dSph). Now with more sensitive instruments on board Chandra and XMM-Newton we can reach fainter luminosity levels. We report on an observation of the Sagittarius (Sgr) dSph made using Chandra and an observation of the Carina (Car) dSph made using XMM-Newton. Our observations are sensitive to sources with X-ray luminosities in the 0.1-10keV band of ∼1x1032erg/s and 3x1034erg/s for the Sgr and Car fields respectively. We have identified a total of 80 sources in the Sgr field and 53 sources in the Car field. Although the source numbers are roughly consistent with the expected number of background AGN, we found a small fraction of X-ray sources which were soft and could be located in the host dSph. Follow-up optical/IR observations may help to identify their optical counterparts and hence determine their nature. Description: Sgr was observed with Chandra ACIS-I for 30ks on 2003 Sep. 3. Car was observed by XMM-Newton on 2005 May 25 for 41.7ks. File Summary:
FileName Lrecl Records Explanations
ReadMe 80 . This file tablea1.dat 91 80 The X-ray sources found in the Chandra observations of the Sgr field tablea2.dat 87 53 The X-ray sources in the Carina field as detected using XMM-Newton
See also: J/AJ/110/1141 : Variables in the Sagittarius dSph (Mateo+ 1995) J/AJ/119/1760 : M54 and Sgr dSph VI photometry (Layden+, 2000) J/A+A/414/503 : Abundances in the Sgr dSph (Bonifacio+, 2004) J/AJ/130/2677 : Stars in the Carina dSph galaxy field (Majewski+, 2005) J/A+A/465/815 : Abundances of Sgr dSph stars (Sbordone+, 2007) Byte-by-byte Description of file: tablea1.dat
Bytes Format Units Label Explanations
1- 3 I3 --- Seq Sequential number, [RW2006c] Sgr NN 5- 6 I2 h RAh Right ascension (J2000) 8- 9 I2 min RAm Right ascension (J2000) 11- 15 F5.2 s RAs Right ascension (J2000) 17 A1 --- DE- Declination sign (J2000) 18- 19 I2 deg DEd Declination (J2000) 21- 22 I2 arcmin DEm Declination (J2000) 24- 27 F4.1 arcsec DEs Declination (J2000) 29- 33 F5.1 10-4ct/s CR0.3-8 Count rate in 0.3-8keV band (ct/10ks) 35- 37 F3.1 10-4ct/s e_CR0.3-8 rms uncertainty on CR0.3-8keV 39- 42 F4.1 10-4ct/s CR0.3-1 Count rate in 0.3-1keV band 44- 46 F3.1 10-4ct/s e_CR0.3-1 rms uncertainty on CR0.3-1keV 48- 51 F4.1 10-4ct/s CR1-2 Count rate in 1-2keV band 53- 55 F3.1 10-4ct/s e_CR1-2 rms uncertainty on CR1-2keV 57- 60 F4.1 10-4ct/s CR2-8 Count rate in 2-8keV band 62- 64 F3.1 10-4ct/s e_CR2-8 rms uncertainty on CR2-8keV 66- 70 F5.2 --- HR1 Hardness ratio, HR1=(H-M)/(H+M+S) (1) 72- 75 F4.2 --- e_HR1 rms uncertainty on HR1 77- 81 F5.2 --- HR2 Hardness ratio, HR2=(M-S)/(H+M+S) (1) 83- 86 F4.2 --- e_HR2 rms uncertainty on HR2 88- 91 F4.1 mag Rmag ? Magnitude, close to the UCAC2 R magnitude
Note (1): Hardness ratios, where HR1=(H-M)/(H+M+S) and HR2=(M-S)/(H+M+S), where H is the counts in the 2-8 keVband, M the counts in the 1-2keV band and S the counts in the 0.3-1keV band.
Byte-by-byte Description of file: tablea2.dat
Bytes Format Units Label Explanations
1- 2 I2 --- Seq Sequential number, [RW2006c] Car NN 4 I1 h RAh Right ascension (J2000) 6- 7 I2 min RAm Right ascension (J2000) 9- 12 F4.1 s RAs Right ascension (J2000) 14 A1 --- DE- Declination sign (J2000) 15- 16 I2 deg DEd Declination (J2000) 18- 19 I2 arcmin DEm Declination (J2000) 21- 24 F4.1 arcsec DEs Declination (J2000) 26- 29 F4.1 ct/ks CR0.2-10 Count rate in 0.2-10keV band (1) 31- 33 F3.1 ct/ks e_CR0.2-10 rms uncertainty on CR0.2-10keV 35- 38 F4.1 ct/ks CR0.2-1 Count rate in 0.2-1keV band (1) 40- 42 F3.1 ct/ks e_CR0.2-1 rms uncertainty on CR0.2-1keV 44- 47 F4.1 ct/ks CR1-2 Count rate in 1-2keV band (1) 49- 51 F3.1 ct/ks e_CR1-2 rms uncertainty on CR1-2keV 53- 56 F4.1 ct/ks CR2-10 Count rate in 2-10keV band (1) 58- 60 F3.1 ct/ks e_CR2-10 rms uncertainty on CR2-10keV 62- 66 F5.2 --- HR1 Hardness ratio, HR1=(H-M)/(H+M+S) (2) 68- 71 F4.2 --- e_HR1 rms uncertainty on HR1 73- 77 F5.2 --- HR2 Hardness ratio, HR2=(M-S)/(H+M+S) (2) 79- 82 F4.2 --- e_HR2 rms uncertainty on HR1 84- 87 F4.1 mag Rmag ? Magnitude, close to UCAC2 R magnitude
Note (1): The count rates refer to that detected in the EPIC MOS(1+2) detector, or the equivalent if detected only in the EPIC pn detector. Note (2): Hardness ratios, where HR1=(H-M)/(H+M+S) and HR2=(M-S)/(H+M+S), where H is the counts in the 2-10keV band, M the counts in the 1-2keV band and S the counts in the 0.2-1keV band.
History: From electronic version of the journal
(End) Patricia Vannier [CDS] 18-May-2007
|The document above follows the rules of the Standard Description for Astronomical Catalogues.From this documentation it is possible to generate f77 program to load files into arrays or line by line|