X‐Ray Processing of ChaMPlane Fields: Methods and Initial Results for Selected Anti–Galactic Center Fields

Hong, J.; Berg, M. van den; Schlegel, Eric M.; Grindlay, Jonathan E.; Koenig, X.; Laycock, S.; Zhao, Ping

doi:10.1086/496966

Cited by 112 publications

(135 citation statements)

References 16 publications

Supporting

Mentioning

129

Contrasting

Order By: Relevance

“…Only three of the 22 X-ray counterparts lie farther than the Hong et al (2005) 95% error circle from the radio position, suggesting that most of the X-ray counterparts are correct counterparts. Two of the three counterparts which are farther than expected from their radio positions (R and L) lie in the wings (1.5" and 2.6" distance, respectively) of brighter sources, which is likely to affect their estimated X-ray positions.…”

Section: Astrometric Correctionsmentioning

confidence: 92%

Chandra studies of the globular cluster 47 Tucanae: a deeper X-ray source catalogue, five new X-ray counterparts to millisecond radio pulsars and new constraints to r-mode instability window

Bhattacharya

Heinke

Chugunov

et al. 2017

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

We combined Chandra ACIS observations of the globular cluster 47 Tucanae (hereafter, 47 Tuc) from 2000, 2002, and 2014-15 to create a deeper X-ray source list, and study some of the faint radio millisecond pulsars (MSPs) present in this cluster. We have detected 370 X-ray sources within the half-mass radius (2 .79) of the cluster, 81 of which are newly identified, by including new data and using improved source detection techniques. The majority of the newly identified sources are in the crowded core region, indicating cluster membership. We associate five of the new X-ray sources with chromospherically active BY Dra or W UMa variables identified by Albrow et al. (2001). We present alternative positions derived from two methods, centroiding and image reconstruction, for faint, crowded sources. We are able to extract X-ray spectra of the recently discovered MSPs 47 Tuc aa, 47 Tuc ab, the newly timed MSP 47 Tuc Z, and the newly resolved MSPs 47 Tuc S and 47 Tuc F. Generally, they are well fit by black body or neutron star atmosphere models, with temperatures, luminosities and emitting radii similar to those of other known MSPs in 47 Tuc, though 47 Tuc aa and 47 Tuc ab reach lower X-ray luminosities. We limit X-ray emission from the full surface of the rapidly spinning (542 Hz) MSP 47 Tuc aa, and use this limit to put an upper bound for amplitude of r-mode oscillations in this pulsar as α < 2.5 × 10 −9 and constrain the shape of the r-mode instability window.

show abstract

Section: Astrometric Correctionsmentioning

confidence: 92%

Chandra studies of the globular cluster 47 Tucanae: a deeper X-ray source catalogue, five new X-ray counterparts to millisecond radio pulsars and new constraints to r-mode instability window

Bhattacharya

Heinke

Chugunov

et al. 2017

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…5 from Hong et al (2005), which gives the 95% confidence radius on the wavdetect position, P err . The wavdetect routine provides us with the source positions, but is not optimised to measure source counts.…”

Section: X-ray Source Detection and Source Characterisationmentioning

confidence: 99%

A Chandra X-Ray Census of the Interacting Binaries in Old Open Clusters—Collinder 261

Vats

Berg

2017

ApJ

View full text Add to dashboard Cite

We present the first X-ray study of Collinder 261 (Cr 261), which at an age of 7 Gyr is one of the oldest open clusters known in the Galaxy. Our observation with the Chandra X-ray Observatory is aimed at uncovering the close interacting binaries in Cr 261, and reaches a limiting X-ray luminosity of L X ≈ 4 × 10 29 erg s −1 (0.3-7 keV) for stars in the cluster. We detect 107 sources within the cluster half-mass radius r h , and we estimate that among the sources with L X 10 30 erg s −1 , ∼26 are associated with the cluster. We identify a mix of active binaries and candidate active binaries, candidate cataclysmic variables, and stars that have "straggled" from the main locus of Cr 261 in the colour-magnitude diagram. Based on a deep optical source catalogue of the field, we estimate that Cr 261 has an approximate mass of 6500 M ⊙ , roughly the same as the old open cluster NGC 6791. The X-ray emissivity of Cr 261 is similar to that of other old open clusters, supporting the trend that they are more luminous in X-rays per unit mass than old populations of higher (globular clusters) and lower (the local neighbourhood) stellar density. This implies that the dynamical destruction of binaries in the densest environments is not solely responsible for the observed differences in X-ray emissivity.

show abstract

“…Source detection was performed with the wavdetect algorithm, on images extracted in three energy bands (Bx = 0.3-8 keV, Sx = 0.3-2.5 keV, and Hx = 2.5-8 keV) at spatial scales of 1, 2, 4, 8, and 16 pixels. X-ray source properties were measured using the aperture photometry procedure described by Hong et al (2005), which accounts for neighboring sources with overlapping source or background regions. The full position-dependent instrument sensitivity is accounted for by application of the exposure maps and response matrices (RMFs and ARFs) generated by the ChaMP pipeline.…”

Section: Observations and Data Reductionmentioning

confidence: 99%

“…The full position-dependent instrument sensitivity is accounted for by application of the exposure maps and response matrices (RMFs and ARFs) generated by the ChaMP pipeline. Positional error circles are assigned to each source based on net counts and distance from the aim point, according to the standard model of Hong et al (2005) which is based on detailed simulations of the full Chandra optical path and ACIS characteristics. Source detection and photometry were performed both on the individual exposures in Table 1 and the complete stacked data set for each field.…”

Section: Observations and Data Reductionmentioning

confidence: 99%

“…Energy-band choices made in generating hardness ratios and color indices inevitably lead to some sources having a gross imbalance in the number of counts in each band. Following the methods of Hong et al (2005), background corrected quantile values (QDx and QDy) were computed from each source's event list photon energy distribution, and spectral model grids were generated using the full Chandra ACIS-I response function (ARF and RMF). The quantile values, along with overplotted model grids for absorbed power law and thermal bremsstrahlung (TB), are plotted in Figure 20 for a series of cuts in signal-tonoise ratio (S/N > 3, >5, >10).…”

Section: Spectral Analysismentioning

confidence: 99%

See 1 more Smart Citation

Exploring the Small Magellanic Cloud to the Faintest X-Ray Fluxes: Source Catalog, Timing, and Spectral Analysis

Laycock

Zezas

Hong

et al. 2010

ApJ

Self Cite

View full text Add to dashboard Cite

We present the results of a pair of 100 ks Chandra observations in the Small Magellanic Cloud (SMC) to survey high-mass X-ray binaries (HMXBs), stars, and low-mass X-ray binaries (LMXBs)/cataclysmic variables down to L x = 4.3 × 10 32 erg s −1 . The two SMC Deep Fields (DFs) are located in the most active star-forming region of the bar, with Deep Field-1 positioned at the most pulsar-rich location identified from previous surveys. Two new pulsars were discovered in the outburst: CXOU J004929.7-731058 (P = 892 s), CXOU J005252.2-721715 (P = 326 s), and three new HMXB candidates were identified. Of the 15 Be-pulsars now known in the field, 13 were detected, with pulsations seen in 9 of them. Ephemerides demonstrate that 6 of the 10 pulsars known to exhibit regular outbursts were seen outside their periastron phase, and quiescent X-ray emission at L X = 10 33 -10 34 erg s −1 is shown to be common. Comparison with ROSAT, ASCA, and XMM-Newton catalogs resulted in positive identification of several previously ambiguous sources. Bright optical counterparts exist for 40 of the X-ray sources, of which 33 are consistent with early-type stars (M V < −2, B −V < 0.2), and are the subject of a companion paper. The results point to an underlying HMXB population density up to double that of active systems. The full catalog of 394 point sources is presented along with detailed analyses of timing and spectral properties.

show abstract

X‐Ray Processing of ChaMPlane Fields: Methods and Initial Results for Selected Anti–Galactic Center Fields

Cited by 112 publications

References 16 publications

Chandra studies of the globular cluster 47 Tucanae: a deeper X-ray source catalogue, five new X-ray counterparts to millisecond radio pulsars and new constraints to r-mode instability window

Chandra studies of the globular cluster 47 Tucanae: a deeper X-ray source catalogue, five new X-ray counterparts to millisecond radio pulsars and new constraints to r-mode instability window

A Chandra X-Ray Census of the Interacting Binaries in Old Open Clusters—Collinder 261

Exploring the Small Magellanic Cloud to the Faintest X-Ray Fluxes: Source Catalog, Timing, and Spectral Analysis

Contact Info

Product

Resources

About