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Timing and spectral analysis of the unusual X-ray transient XTE J0421+560/CI Camelopardalis
Bartlett, E. S.; Coe, M. J.; Uttley, P. +2 more
We present a detailed X-ray study of the 2003 XMM-Newton observation of the high-mass X-ray binary XTE J0421+560/CI Camelopardalis. The continuum of the X-ray spectrum is well described by a flat power law (Γ = 1.0 ± 0.2) with a large intrinsic absorbing column (NH = (4.4 ± 0.5) × 1023 cm-2). We have decomposed the…
The nature of the H2-emitting gas in the Crab nebula
Richardson, C. T.; Fabian, A. C.; Ferland, G. J. +4 more
Understanding how molecules and dust might have formed within a rapidly expanding young supernova remnant is important because of the obvious application to vigorous supernova activity at very high redshift. In previous papers, we have mapped the Crab nebula (the Crab) in a rotovibrational H2 emission line, and then measured the molecul…
Emission spectrum of ionized gas in the irregular galaxy Holmberg II
Moiseev, A. V.; Lozinskaya, T. A.; Egorov, O. V.
We studied the ionized gas spectra of star-forming regions in the Holmberg II galaxy using optical long-slit spectroscopic observations made with the 6-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences (SAO RAS). We estimated the oxygen, nitrogen, sulphur, neon and argon abundances in individual H II regions a…
Serendipitous detection of an overdensity of Herschel-SPIRE 250 µm sources south of MRC 1138-26
Berta, S.; Altieri, B.; Dannerbauer, H. +9 more
We report the serendipitous detection of a significant overdensity of Herschel-Spectral and Photometric Imaging Receiver 250 µm sources in the vicinity of MRC 1138-26. We use an adaptive kernel density estimate to quantify the significance, including a comparison with other fields. The overdensity has a size of ∼3.5-4 arcmin and stands out a…
X-ray absorption variability in NGC 4507
Elvis, Martin; Risaliti, Guido; Nardini, Emanuele +5 more
We present a complete spectral analysis of an XMM-Newton and Chandra campaign of the obscured AGN in NGC 4507, consisting of six observations spanning a period of six months, ranging from 2010 June to December. We detect strong absorption variability on time-scales between 1.5 and 4 months, suggesting that the obscuring material consists of gas cl…
An outburst scenario for the X-ray spectral variability in 3C 111
Reynolds, C. S.; García, J.; Lohfink, A. +2 more
We present a combined Suzaku and Swift BAT broad-band E = 0.6-200 keV spectral analysis of three 3C 111 observations obtained in 2010. The data are well described with an absorbed power-law continuum and a weak (R ≃ 0.2) cold reflection component from distant material. We constrain the continuum cutoff at EC ≃ 150-200 keV, which is in a…
The spatial extent and distribution of star formation in 3D-HST mergers at z ∼ 1.5
Maseda, Michael V.; Schmidt, Kasper B.; Franx, Marijn +14 more
We present an analysis of the spatial distribution of star formation in a sample of 60 visually identified galaxy merger candidates at z > 1. Our sample, drawn from the 3D-HST survey, is flux limited and was selected to have high star formation rates based on fits of their broad-band, low spatial resolution spectral energy distributions. It inc…
XMM-Newton observation of the highly magnetized accreting pulsar Swift J045106.8-694803: evidence of a hot thermal excess
Bartlett, E. S.; Coe, M. J.; Ho, W. C. G.
Several persistent, low-luminosity (LX ∼ 1034 erg s-1), long-spin-period (P > 100 s) high-mass X-ray binaries have been reported with blackbody components with temperatures >1 keV. These hot thermal excesses have correspondingly small emitting regions (<1 km2) and are attributed to the neutron s…
Probing the extended gaseous regions of M31 with quasar absorption lines
Turnshek, David A.; Rao, Sandhya M.; York, Donald G. +4 more
We present Hubble Space Telescope Cosmic Origins Spectrograph spectra of 10 quasars located behind M31, selected to investigate the properties of gas associated with its extended disc and high-velocity clouds (HVCs). The sightlines have impact parameters ranging between b = 13 and 112 kpc. No absorption is detected in the four sightlines selected …
An O2If* star found in isolation in the backyard of NGC 3603.
Roman-Lopes, A.
In this Letter, we communicate the identification of a new Galactic O2If* star (MTT 68) isolated at a projected linear distance of 3 pc from the centre of the starburst cluster NGC 3603. From its optical photometry, I computed a bolometric luminosity MBol = -10.7, which corresponds to a total stellar luminosity of 1.5 × 106 L…