CHANDRA detection of 16 new X-ray sources

Yoldas, AK
Balman, Şölen
We have detected 18 sources over 6sigma threshold within two regions 8'.3 x 16'.9 and 8'.3 x 33'.6 in the vicinity of the point with alpha = 03(h)31(m)02.(s)45 (J2000) and delta = +43degrees47'58".5 (J2000) using a CHANDRA ACIS (S+I) observation. Two of the sources were detected before with ROSAT HRI and one source could be closely identified with a star in the optical catalog, USNO A-2. We have also studied source spectra applying four spectral models to the data. Most of the sources can be classified as Cataclysmic Variable, Low Mass X-ray Binary or single star candidates due to their spectral characteristics and luminosities. We also searched for the extragalactic origin for these 18 sources. The source count rates vary between 5.8x10(-4) -4.7x10(-3) counts/s. Due to low count rates temporal characteristics of the sources can not be studied effectively.


Pulsar braking indices, glitches and energy dissipation in neutron stars
Alpar, M. Ali; Baykal, Altan (Oxford University Press (OUP), 2006-10-11)
Almost all pulsars with anomalous positive Omega measurements (corresponding to anomalous braking indices in the range 5 <vertical bar n vertical bar < 100), including all the pulsars with observed large glitches (Delta Omega/Omega > 10(-7)) as well as post-glitch or interglitch Omega measurements, obey the scaling between Omega and glitch parameters originally noted in the Vela pulsar. Negative second derivative values can be understood in terms of glitches that were missed or remained unresolved. We discu...
Acciari, V. A.; et. al. (IOP Publishing, 2009-08-01)
We present results from a long-term monitoring campaign on the TeV binary LSI +61 degrees 303 with VERITAS at energies above 500 GeV, and in the 2-10 keV hard X-ray bands with RXTE and Swift, sampling nine 26.5 day orbital cycles between 2006 September and 2008 February. The binary was observed by VERITAS to be variable, with all integrated observations resulting in a detection at the 8.8 sigma (2006/2007) and 7.3 sigma (2007/2008) significance level for emission above 500 GeV. The source was detected durin...
Reconstructed density and velocity fields from the 2MASS Redshift Survey
Erdogdu, Pirin; Lahav, Ofer; Huchra, John P.; Colless, Matthew; Cutri, Roc M.; Falco, Emilio; George, Teddy; Jarrett, Thomas; Jones, D. Heath; Macri, Lucas M.; Mader, Jeff; Martimbeau, Nathalie; Pahre, Michael A.; Parker, Quentin A.; Rassat, Anaid; Saunders, Will (Oxford University Press (OUP), 2006-11-21)
W We present the reconstructed real-space density and the predicted velocity fields from the Two-Micron All-Sky Redshift Survey (2MRS). The 2MRS is the densest all-sky redshift survey to date and includes about 23 200 galaxies with extinction-corrected magnitudes brighter than K-s = 11.25. Our method is based on the expansion of these fields in Fourier-Bessel functions. Within this framework, the linear redshift distortions only affect the density field in the radial direction and can easily be deconvolved ...
Swift observations of CSS081007:030559+054715
Beardmore, A. P.; Osborne, J. P.; Page, K. L.; Schwarz, G.; Starrfield, S.; Hakala, P.; Ness, J. -U.; Balman, Şölen; Wagner, R. M. (Wiley, 2010-02-01)
CSS081007:030559+054715 was discovered by the Catalina Real-time Transient Survey. Optical spectroscopy revealed a multi-peaked Ha emission line profile with radial velocities exceeding 1500 km/s, as well as strong Ne emission, suggestive of a neon nova. We monitored the source extensively with the Swift satellite, obtaining a unique dataset spanning 270 days in the soft X-ray and UV bands. The data reveal a soft, blackbody-like spectrum with a temperature around 55 eV (though dependent on the modelling), v...
Recent timing studies on RXTE observations of 4U 1538-52
Baykal, Altan; Beklen, E. (EDP Sciences, 2006-07-01)
The high mass X-ray binary pulsar 4U 1538-52 was observed between July 31 and August 7, 2003. Using these observations, we determined new orbital epochs for both circular and elliptical orbit models. The orbital epochs for both orbit solutions agreed with each other and yielded an orbital period derivative. P/P = (0.4 +/- 1.8) x 10(-6) yr(-1). This value is consistent with the earlier measurement P/P = (2.9 +/- 2.1) x 10(-6) yr(-1) at the 1 sigma level and gives only an upper limit to the orbital period dec...
Citation Formats
A. Yoldas and Ş. Balman, “CHANDRA detection of 16 new X-ray sources,” ASTRONOMY & ASTROPHYSICS, pp. 190–194, 2002, Accessed: 00, 2020. [Online]. Available: