Discovery of an ultra-luminous X-ray source candidate, ULX (X-8) in NGC 3384 with Chandra

• Published in: Astrophysics and space science Vol. 354; no. 2; pp. 535 - 540
• Main Authors: Devi, A. Senorita, Singh, K. Yugindro
• Format: Journal Article
• Language: English
• Published: Dordrecht Springer Netherlands 01-12-2014; Springer Nature B.V
• Subjects: Astrobiology; Astronomy; Astrophysics; Astrophysics and Astroparticles; Binary stars; Blackbody; Cosmology; Disks; Luminosity; Observations and Techniques; Original Article; Physics; Physics and Astronomy; Point sources; Signatures; Space Exploration and Astronautics; Space Sciences (including Extraterrestrial Physics; Spectra; Stars & galaxies; X-ray astronomy; X-ray sources; X-rays; Galaxies: individual (NGC 3384); X-rays: binaries
• ISSN: 0004-640X; 1572-946X
• DOI: 10.1007/s10509-014-2091-8

The present paper aims to study the previously unstudied Chandra observed X-ray point sources of NGC 3384. While most of the point sources in NGC 3384 are hard X-ray binaries, we report here the discovery of a candidate Ultra-luminous X-ray source (ULX), X-8 in NGC 3384 during an effective 28.67 ks Chandra observation. ULX, X-8 is found to have its 0.3–10.0 keV luminosity ∼1.52×10
39
ergs s
−1
and a bolometric luminosity ∼2.43×10
39
ergs s
−1
. The ULX is spectrally hard in X-rays, with
Γ
∼1.97 when fitted with an absorbed powerlaw. The spectral property of this object, when fitted with an absorbed disk blackbody, appears to be consistent with nearly a 30
M
⊙
black hole accreting at ∼0.58 times its Eddington luminosity. The lightcurve of this ULX source, X-8 has shown no signature of short-term variability in kilo-seconds time scales in the present available Chandra observation.