scholarly journals Deep XMM-Newton observations of the northern disc of M 31

2018 ◽  
Vol 620 ◽  
pp. A28 ◽  
Author(s):  
Manami Sasaki ◽  
Frank Haberl ◽  
Martin Henze ◽  
Sara Saeedi ◽  
Benjamin F. Williams ◽  
...  
Keyword(s):  
Spectral Properties ◽  
Supernova Remnants ◽  
X Ray ◽  
Star Forming ◽  
Transient Source ◽  
Upper Limits ◽  
Low Mass ◽  
Higher Temperature ◽  
M 31 ◽  
X Ray Binaries

Context. We carried out new observations of two fields in the star-forming northern ring of M 31 with XMM-Newton with each one of them consisting of two exposures of about 100 ks each. A previous XMM-Newton survey of the entire M 31 galaxy revealed extended diffuse X-ray emission in these regions. Aims. We study the population of X-ray sources in the northern disc of M 31 by compiling a complete list of X-ray sources down to a sensitivity limit of ∼7 × 1034 erg s−1 (0.5–2.0 keV) and improve the identification of the X-ray sources. The major objective of the observing programme was the study of the hot phase of the interstellar medium (ISM) in M 31. The analysis of the diffuse emission and the study of the ISM is presented in a separate paper. Methods. We analysed the spectral properties of all detected sources using hardness ratios and spectra if the statistics were high enough. We also checked for variability. In order to classify the sources detected in the new deep XMM-Newton observations, we cross-correlated the source list with the source catalogue of a new survey of the northern disc of M 31 carried out with the Chandra X-ray Observatory and the Hubble Space Telescope (Panchromatic Hubble Andromeda Treasury, PHAT) as well as with other existing catalogues. Results. We detected a total of 389 sources in the two fields of the northern disc of M 31 observed with XMM-Newton. We identified 43 foreground stars and candidates and 50 background sources. Based on a comparison with the results of the Chandra/PHAT survey, we classify 24 hard X-ray sources as new candidates for X-ray binaries. In total, we identified 34 X-ray binaries and candidates and 18 supernova remnants (SNRs) and candidates. We studied the spectral properties of the four brightest SNRs and confirmed five new X-ray SNRs. Three of the four SNRs, for which a spectral analysis was performed, show emission mainly below 2 keV, which is consistent with shocked ISM. The spectra of two of them also require an additional component with a higher temperature. The SNR [SPH11] 1535 has a harder spectrum and might suggest that there is a pulsar-wind nebula inside the SNR. For all SNRs in the observed fields, we measured the X-ray flux or calculated upper limits. We also carried out short-term and long-term variability studies of the X-ray sources and found five new sources showing clear variability. In addition, we studied the spectral properties of the transient source SWIFT J004420.1+413702, which shows significant variation in flux over a period of seven months (June 2015 to January 2016) and associated change in absorption. Based on the likely optical counterpart detected in the Chandra/PHAT survey, the source is classified as a low-mass X-ray binary.

scholarly journals An X-Ray View of Interacting Binaries Outside The Galaxy

2004 ◽  
Vol 194 ◽  
pp. 3-6
Author(s):  
Andrea H. Prestwich
Keyword(s):  
Supernova Remnants ◽  
Luminosity Function ◽  
Local Group ◽  
Spiral Galaxies ◽  
High Mass ◽  
X Ray ◽  
Star Forming ◽  
Star Forming Regions ◽  
Low Mass ◽  
X Ray Binaries

AbstractChandra and XMM-Newton are revolutionizing our understanding of compact binaries in external galaxies, allowing us to study sources in detail in Local Group Galaxies and study populations in more distant systems. In M31 the X-ray luminosity function depends on the local stellar population in the sense that areas with active star formation have more high luminosity sources, and a higher overall source density (Kong. Di Stefano. Garcia, & Greiner 2003). This result is also true in galaxies outside the Local Group; starburst galaxies have flatter X-ray luminosity functions than do spiral galaxies which are in turn flatter than elliptical galaxies. These observational results suggest that the high end of the luminosity function in star forming regions is dominated by short-lived high mass X-ray binaries.In Chandra Cycle 2 we started a Large Project to survey a sample of 11 nearby (< 10Mpc) face-on spiral galaxies. We find that sources can be approximately classified on the basis of their X-ray color into low mass X-ray binaries, high mass X-ray binaries and supersoft sources. There is an especially interesting class of source that has X-ray colors softer (“redder”) than a typical low mass X-ray binary source, but not so extreme as supersoft sources. Most of these are probably X-ray bright supernova remnants, but some may be a new type of black hole accretor. Finally, when we construct a luminosity function of sources selecting only sources with low mass X-ray binary colors (removing soft sources) we find that there is a dip or break probably associated with the Eddington luminosity for a neutron star.

scholarly journals Accreting Neutron Stars

1987 ◽  
Vol 125 ◽  
pp. 135-148
Author(s):  
N.E. White
Keyword(s):  
Magnetic Field ◽  
Field Strength ◽  
Neutron Stars ◽  
Magnetic Field Strength ◽  
Spectral Properties ◽  
High Mass ◽  
X Ray ◽  
Temporal Properties ◽  
Low Mass ◽  
X Ray Binaries

This paper reviews accreting neutron stars in X-ray binaries, with particular emphasis on how variations in magnetic field strength may be responsible for explaining the spectral and temporal properties observed from the various systems. This includes a review of X-ray pulsars in both low and high mass systems, and a discussion of the spectral properties of the low mass X-ray binaries.

scholarly journals Quasi-simultaneous radio and X-ray observations of Aql X-1 : probing low luminosities

2019 ◽  
Vol 492 (2) ◽  
pp. 2858-2871 ◽  
Author(s):  
N V Gusinskaia ◽  
J W T Hessels ◽  
N Degenaar ◽  
A T Deller ◽  
J C A Miller-Jones ◽  
...  
Keyword(s):  
Neutron Star ◽  
Large Array ◽  
Very Large Array ◽  
X Ray ◽  
Upper Limits ◽  
Order Of Magnitude ◽  
Low Mass ◽  
Low X ◽  
Power Law Index ◽  
X Ray Binaries

ABSTRACT Aql X-1 is one of the best-studied neutron star low-mass X-ray binaries. It was previously targeted using quasi-simultaneous radio and X-ray observations during at least seven different accretion outbursts. Such observations allow us to probe the interplay between accretion inflow (X-ray) and jet outflow (radio). Thus far, these combined observations have only covered one order of magnitude in radio and X-ray luminosity range; this means that any potential radio–X-ray luminosity correlation, LR ∝ LXβ, is not well constrained (β ≈ 0.4–0.9, based on various studies) or understood. Here we present quasi-simultaneous Very Large Array and Swift-XRT observations of Aql X-1’s 2016 outburst, with which we probe one order of magnitude fainter in radio and X-ray luminosity compared to previous studies (6 × 1034 erg s−1 &lt; LX &lt;3 × 1035 erg s−1, i.e. the intermediate to low-luminosity regime between outburst peak and quiescence). The resulting radio non-detections indicate that Aql X-1’s radio emission decays more rapidly at low X-ray luminosities than previously assumed – at least during the 2016 outburst. Assuming similar behaviour between outbursts, and combining all available data in the hard X-ray state, this can be modelled as a steep β =$1.17^{+0.30}_{-0.21}$ power-law index or as a sharp radio cut-off at LX ≲ 5 × 1035 erg s−1 (given our deep radio upper limits at X-ray luminosities below this value). We discuss these results in the context of other similar studies.

scholarly journals EUV Constraints on Models of Low Mass X-Ray Binaries

1996 ◽  
Vol 152 ◽  
pp. 425-429
Author(s):  
D.J. Christian ◽  
J.E. Edelstein ◽  
M. Mathioudakis ◽  
K. McDonald ◽  
M.M. Sirk
Keyword(s):  
X Ray ◽  
Upper Limits ◽  
Spectral Models ◽  
Two Component ◽  
Survey Results ◽  
Low Mass ◽  
X Ray Binaries ◽  
Thermal Bremsstrahlung

We present EUVE survey results for moderate column directions containing known low-mass X-ray binaries (LMXB). We derive Lexan band (100 Å) count rates and upper limits for nearly 40 LMXB chosen generally with EB-V ≤ 0.3. Detections include Sco X-1, Her X-1, and the GRO transient CJ0422+32. Super soft sources in the LMC yield 3 σ upper limits of ≤ 10 counts ks−1. The extrapolation of two component spectral models (such as blackbody plus thermal bremsstrahlung), are in agreement with the survey upper limits. Contemporary LMXB spectral models, which involve Comptonization in an inner disk corona, predict a large flux of EUV photons. If the above model is correct in the EUV, such a component could be detected in source with low column densities. We argue that additional intrasystem column hampers its detection.

scholarly journals GAMA/XXL: X-ray point sources in low-luminosity galaxies in the GAMA G02/XXL-N field

2021 ◽  
Vol 502 (2) ◽  
pp. 3101-3112
Author(s):  
E Nwaokoro ◽  
S Phillipps ◽  
A J Young ◽  
I Baldry ◽  
A Bongiorno ◽  
...  
Keyword(s):  
Positional Information ◽  
Point Sources ◽  
High Mass ◽  
X Ray ◽  
Star Forming ◽  
Flux Limit ◽  
The Galaxy ◽  
Low Mass ◽  
Mass Assembly ◽  
X Ray Binaries

ABSTRACT Relatively few X-ray sources are known that have low-mass galaxies as hosts. This is an important restriction on studies of active galactic nuclei (AGNs), hence black holes, and of X-ray binaries (XRBs) in low-mass galaxies; addressing it requires very large samples of both galaxies and X-ray sources. Here, we have matched the X-ray point sources found in the XXL-N field of the XXL survey (with an X-ray flux limit of ∼6 × 10−15 erg s−1 cm−2 in the [0.5–2] keV band) to galaxies with redshifts from the Galaxy And Mass Assembly (GAMA) G02 survey field (down to a magnitude limit r = 19.8) in order to search for AGNs and XRBs in GAMA galaxies, particularly those of low optical luminosity or stellar mass (fainter than Mr = −19 or $M_* \lesssim 10^{9.5}\, \mathrm{M}_{\odot }$). Out of a total of 1200 low-mass galaxies in the overlap region, we find a total of 28 potential X-ray source hosts, though this includes possible background contaminants. From a combination of photometry (optical and infrared colours), positional information, and optical spectra, we deduce that most of the ≃20 X-ray sources genuinely in low-mass galaxies are high-mass X-ray binaries in star-forming galaxies. None of the matched sources in a low-mass galaxy has a BPT classification as an AGN, and even ignoring this requirement, none passes both criteria of close match between the X-ray source position and optical galaxy centre (separation ≤3 arcsec) and high [O iii] line luminosity (above 1040.3 erg s−1).

X‐Ray Spectral Properties of Low‐Mass X‐Ray Binaries in Nearby Galaxies

2003 ◽  
Vol 587 (1) ◽  
pp. 356-366 ◽  
Author(s):  
Jimmy A. Irwin ◽  
Alex E. Athey ◽  
Joel N. Bregman
Keyword(s):  
Spectral Properties ◽  
X Ray ◽  
Nearby Galaxies ◽  
Low Mass ◽  
X Ray Binaries

scholarly journals Stellar binaries that survive supernovae

2019 ◽  
Vol 485 (4) ◽  
pp. 5394-5410 ◽  
Author(s):  
C S Kochanek ◽  
K Auchettl ◽  
K Belczynski
Keyword(s):  
Supernova Remnants ◽  
Reasonable Agreement ◽  
Main Sequence ◽  
High Mass ◽  
Core Collapse ◽  
Population Synthesis ◽  
X Ray ◽  
Upper Limits ◽  
Model Finding ◽  
X Ray Binaries

Abstract The number of binaries containing black holes (BH) or neutron stars (NS) depends critically on the fraction of binaries that survive supernova (SN) explosions. We searched for surviving star plus remnant binaries in a sample of 49 supernova remnants (SNR) containing 23 previously identified compact remnants and three high-mass X-ray binaries (HMXB), finding no new interacting or non-interacting binaries. The upper limits on any main-sequence stellar companion are typically $\lesssim 0.2\, \mathrm{M}_\odot$ and are at worst $\lesssim 3\, \mathrm{M}_\odot$. This implies that f &lt; 0.1 of core-collapse SNRs contain a non-interacting binary, and f = 0.083 (0.032 &lt; f &lt; 0.17) contain an interacting binary at 90 per cent confidence. We also find that the transverse velocities of HMXBs are low, with a median of only 12 km s−1 for field HMXBs, so surviving binaries will generally be found very close to the explosion centre. We compare the results to a ‘standard’ StarTrack binary population synthesis (BPS) model, finding reasonable agreement with the observations. In particular, the BPS models predict that 6 per cent of initial binaries leave a star plus remnant binary, or 5 per cent of SNRs assuming an 84 per cent binary fraction.

Iron K-Line Emission from X-Ray Binaries

1988 ◽  
Vol 102 ◽  
pp. 47-50
Author(s):  
K. Masai ◽  
S. Hayakawa ◽  
F. Nagase
Keyword(s):  
Accretion Disk ◽  
Radiative Recombination ◽  
Characteristic Temperature ◽  
Line Emission ◽  
Ionization Front ◽  
Continuum Radiation ◽  
X Ray ◽  
Low Mass ◽  
X Ray Binaries

AbstractEmission mechanisms of the iron Kα-lines in X-ray binaries are discussed in relation with the characteristic temperature Txof continuum radiation thereof. The 6.7 keV line is ascribed to radiative recombination followed by cascades in a corona of ∼ 100 eV formed above the accretion disk. This mechanism is attained for Tx≲ 10 keV as observed for low mass X-ray binaries. The 6.4 keV line observed for binary X-ray pulsars with Tx&gt; 10 keV is likely due to fluorescence outside the He II ionization front.

scholarly journals QPOs in compact binaries from small scale eruptions in an inner magnetized disk

2020 ◽  
Author(s):  
Nicolas Scepi ◽  
Mitchell C Begelman ◽  
Jason Dexter
Keyword(s):  
Rapid Heating ◽  
Small Scale ◽  
Type B ◽  
Periodic Oscillations ◽  
X Ray ◽  
Compact Binaries ◽  
Heating And Cooling ◽  
Low Mass ◽  
X Ray Binaries ◽  
Standard Disk

Abstract Dwarf novæ (DNe) and low mass X-ray binaries (LMXBs) are compact binaries showing variability on time scales from years to less than seconds. Here, we focus on explaining part of the rapid fluctuations in DNe, following the framework of recent studies on the monthly eruptions of DNe that use a hybrid disk composed of an outer standard disk and an inner magnetized disk. We show that the ionization instability, that is responsible for the monthly eruptions of DNe, is also able to operate in the inner magnetized disk. Given the low density and the fast accretion time scale of the inner magnetized disk, the ionization instability generates small, rapid heating and cooling fronts propagating back and forth in the inner disk. This leads to quasi-periodic oscillations (QPOs) with a period of the order of 1000 s. A strong prediction of our model is that these QPOs can only develop in quiescence or at the beginning/end of an outburst. We propose that these rapid fluctuations might explain a subclass of already observed QPOs in DNe as well as a, still to observe, subclass of QPOs in LMXBs. We also extrapolate to the possibility that the radiation pressure instability might be related to Type B QPOs in LMXBs.

scholarly journals Drifts of the marginally stable burning frequency in the X-ray binaries 4U 1608–52 and Aql X–1

2021 ◽  
Vol 502 (2) ◽  
pp. 1856-1863
Author(s):  
G C Mancuso ◽  
D Altamirano ◽  
M Méndez ◽  
M Lyu ◽  
J A Combi
Keyword(s):  
Frequency Drift ◽  
Soft Or ◽  
Significance Level ◽  
X Ray ◽  
Intermediate States ◽  
Source State ◽  
Nuclear Burning ◽  
Low Mass ◽  
X Ray Binaries ◽  
Stable Burning

ABSTRACT We detect millihertz quasi-periodic oscillations (mHz QPOs) using the Rossi X-ray Time Explorer (RXTE) from the atoll neutron-star (NS) low-mass X-ray binaries 4U 1608–52 and Aql X–1. From the analysis of all RXTE observations of 4U 1608–52 and Aql X–1, we find mHz QPOs with a significance level &gt;3σ in 49 and 47 observations, respectively. The QPO frequency is constrained between ∼4.2 and 13.4 mHz. These types of mHz QPOs have been interpreted as being the result of marginally stable nuclear burning of He on the NS surface. We also report the discovery of a downward frequency drift in three observations of 4U 1608–52, making it the third source that shows this behaviour. We only find strong evidence of frequency drift in one occasion in Aql X–1, probably because the observations were too short to measure a significant drift. Finally, the mHz QPOs are mainly detected when both sources are in the soft or intermediate states; the cases that show frequency drift only occur when the sources are in intermediate states. Our results are consistent with the phenomenology observed for the NS systems 4U 1636–53 and EXO 0748–676, suggesting that all four sources can reach the conditions for marginally stable burning of He on the NS surface. These conditions depend on the source state in the same manner in all four systems.

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