<i>ChaMPlane</i>DEEP GALACTIC BULGE SURVEY. I. FAINT ACCRETION-DRIVEN BINARIES IN THE LIMITING WINDOW

Berg, M. van den; Hong, J.; Grindlay, Jonathan E.

doi:10.1088/0004-637x/700/2/1702

Cited by 22 publications

(3 citation statements)

References 44 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is therefore unlikely that this source is an isolated X-ray emitting star. The implied X-ray luminosity and X-ray-to-optical flux ratio are similar to Galactic bulge CVs (van den Berg et al 2009); the observed rapid X-ray variability (see Section 5.5.2) is further consistent with a CV origin (Kuulkers et al 2006). The properties of this source are also consistent with a neutron star accreting from the wind of a late-type giant (e.g., a symbiotic star, similar to GX 1+4; Masetti et al 2006).…”

Section: Ngc 2403supporting

confidence: 58%

THECHANDRALOCAL VOLUME SURVEY. I. THE X-RAY POINT SOURCE POPULATIONS OF NGC 55, NGC 2403, AND NGC 4214

Binder

Williams

Eracleous

et al. 2015

View full text Add to dashboard Cite

We present comprehensive X-ray point source catalogs of NGC 55, NGC 2403, and NGC 4214 as part of the Chandra Local Volume Survey. The combined archival observations have effective exposure times of 56.5 ks, 190 ks, and 79 ks for NGC 55, NGC 2403, and NGC 4214, respectively. When combined with our published catalogs for NGC 300 and NGC 404, our survey contains 629 X-ray sources total down to a limiting unabsorbed luminosity of ∼ 5 × 10 35 erg s −1 in the 0.35-8 keV band in each of the five galaxies. We present X-ray hardness ratios, spectral analysis, radial source distributions, and an analysis of the temporal variability for the X-ray sources detected at high significance. To constrain the nature of each X-ray source, we carried out cross-correlations with multi-wavelength data sets. We searched overlapping Hubble Space Telescope observations for optical counterparts to our X-ray detections to provide preliminary classifications for each X-ray source as a likely X-ray binary, background AGN, supernova remnant, or foreground star.

show abstract

Section: Ngc 2403supporting

confidence: 58%

THECHANDRALOCAL VOLUME SURVEY. I. THE X-RAY POINT SOURCE POPULATIONS OF NGC 55, NGC 2403, AND NGC 4214

Binder

Williams

Eracleous

et al. 2015

View full text Add to dashboard Cite

show abstract

“…The LW is one of the low‐extinction bulge fields, and the first deep Chandra (100 ks) exposure of the region was conducted as a part of our survey to understand the population of Galactic bulge X‐ray sources (van den Berg et al ; H09b; van den Berg, Hong & Grindlay , hereafter V09). Our recent discovery of periodic sources in the LW also indicates a large population of MCVs in the region and their significant role in the resolved hard X‐ray flux (Hong et al , hereafter H12).…”

Section: Introductionmentioning

confidence: 99%

Dominance of magnetic cataclysmic variables in the resolved Galactic ridge X-ray emission of the limiting window

Hong

2012

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

The diffuse appearance of the Galactic ridge X-ray emission has been puzzling since its discovery due to the lack of compelling theories for sustainable hot diffuse X-ray emission in the Galactic plane. Recently, Revnivtsev et al. claimed that ∼90 per cent of the 6.5-7.1 keV X-ray flux from a small section of a low-extinction region at 1. • 4 south of the Galactic Centre has been resolved to discrete sources with L X, 2−10 keV 4 × 10 −16 erg s −1 cm −2 , using ultradeep (1 Ms) observations made by the Chandra X-ray Observatory. They also concluded that coronally active stars such as active binaries (ABs) contribute ∼60 per cent of the resolved flux. However, our recent discovery of a large population of magnetic cataclysmic variables (MCVs) in the same region suggests their significant role in the resolved hard X-ray flux. In addition, deep X-ray surveys of other several Galactic bulge fields over the past decade have indicated that MCVs are likely the major contributor in the hard X-ray emission above 2-3 keV. To solve this mystery, we have conducted an independent in-depth analysis of discrete X-ray sources in the low-extinction region. The total fraction of the 6.5-7.1 keV flux we can confidently claim as resolved is ∼70-80 per cent, which largely agrees with Revnivtsev et al., but leaves some room for diffuse components. However, despite the various attempts, we consistently find that the resolved hard X-ray flux above 3 keV is dominated by relatively bright, hard X-ray sources such as MCVs, whereas the contribution from relatively faint, soft sources such as ABs is below 20 per cent. We describe in detail our analysis procedure in order to elucidate possible origins of the discrepancy.

show abstract

“…The programme utilizes Chandra X‐ray data in combination with follow‐up optical and IR photometric and spectroscopic observations, so as to maximize the number of identified sources and explore the populations thereby revealed. Recent publications from the ChaMPlane programme include a study of Chandra fields in the Galactic anticentre (Hong et al 2005), and the Galactic Centre and bulge (Laycock et al 2005; Koenig et al 2008; Hong et al 2009; van den Berg, Hong & Grindlay 2009).…”

Section: Introductionmentioning

confidence: 99%

The Galactic plane at faint X-ray fluxes - I. Properties and characteristics of the X-ray source population

Warwick¹,

Pérez-Ramírez²,

Byckling³

2011

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We investigate the serendipitous X-ray source population revealed in XMM-Newton observations targeted in the Galactic plane within the region 315 • < l < 45 • and |b| < 2. • 5. Our study focuses on a sample of 2204 X-ray sources at intermediate to faint fluxes, which were detected in a total of 116 XMM-Newton fields and are listed in the Second XMM-Newton Serendipitous Source Catalog. We characterize each source as spectrally soft or hard on the basis of whether the bulk of the recorded counts have energies below or above 2 keV and find that the sample divides roughly equally (56 per cent:44 per cent) into these soft and hard categories. The X-ray spectral form underlying the soft sources may be represented as either a power-law continuum with ∼ 2.5 or a thermal spectrum with kT ∼ 0.5 keV, with N H ranging from 10 20 to 10 22 cm −2 . For the hard sources, a significantly harder continuum form is likely, that is, ∼ 1, with N H = 10 22 -10 24 cm −2 . For ∼50 per cent of the hard sources, the inferred column density is commensurate with the total Galactic line-of-sight value; many of these sources will be located at significant distances across the Galaxy, implying a hard-band luminosity L X > 10 32 erg s −1 , whereas some will be extragalactic interlopers. A high fraction ( 90 per cent) of the soft sources have potential near-infrared (NIR) (Two-Micron All-Sky Survey and/or United Kingdom Infrared Deep Sky Survey) counterparts inside their error circles, consistent with the dominant soft-X-ray-source population being relatively nearby coronally-active stars. These stellar counterparts are generally brighter than J = 16, a brightness cut-off which corresponds to the saturation of the X-ray coronal emission at L X = 10 −3 L bol . In contrast, the success rate in finding likely IR counterparts to the hard X-ray sample is no more than ≈15 per cent down to J = 16 and ≈25 per cent down to J = 20, set against a rapidly rising chance coincidence rate. The make-up of the hard-X-ray-source population, in terms of the known classes of accreting and non-accreting systems, remains uncertain.

show abstract

ChaMPlaneDEEP GALACTIC BULGE SURVEY. I. FAINT ACCRETION-DRIVEN BINARIES IN THE LIMITING WINDOW

Cited by 22 publications

References 44 publications

THECHANDRALOCAL VOLUME SURVEY. I. THE X-RAY POINT SOURCE POPULATIONS OF NGC 55, NGC 2403, AND NGC 4214

THECHANDRALOCAL VOLUME SURVEY. I. THE X-RAY POINT SOURCE POPULATIONS OF NGC 55, NGC 2403, AND NGC 4214

Dominance of magnetic cataclysmic variables in the resolved Galactic ridge X-ray emission of the limiting window

The Galactic plane at faint X-ray fluxes - I. Properties and characteristics of the X-ray source population

Contact Info

Product

Resources

About