The Cartwheel galaxy as a stepping stone for binaries formation

2018 ◽  
Vol 14 (S346) ◽  
pp. 297-306 ◽  
Author(s):  
Anna Wolter ◽  
Guido Consolandi ◽  
Marcella Longhetti ◽  
Marco Landoni ◽  
Andrea Bianco

AbstractUltraluminous X-ray sources (ULXs) are end points of stellar evolution. They are mostly interpreted as binary systems with a massive donor. They are also the most probable progenitors for BH-BH, and even more, for BH-NS coalescence. Parameters of ULXs are not know and need to be better determined, in particular the link with the metallicity of the environment which has been invoked frequently but not proven strongly. We have tackled this problem by using a MUSE DEEP mosaic of the Cartwheel galaxy and applying a Monte Carlo code that jointly fits spectroscopy and photometry. We measure the metallicity of the emitting gas in the ring and at the positions of X-ray sources by constructing spatially resolved emission line ratio maps and BPT diagnostic maps. The Carthweel is the archetypal ring galaxy and the location and formation time of new stellar populations is easier to reconstruct than in more normal galaxies. It has the largest population of ULXs ever observed in a single galaxy (16 sources have been classified as ULXs in Chandra and XMM-Newton data). The Cartwheel galaxy is therefore the ideal laboratory to study the relation between Star Formation (SF Rates and SF History) and number of ULXs and also their final fate. We find that the age of the stellar population in the outer ring is consistent with being produced in the impact (≤300Myr) and that the metallicity is mostly sub-solar, even if solutions can be found with a solar metallicity that account for most observed properties. The findings for the Cartwheel will be a testbed for further modelisation of binary formation and evolution paths.

1996 ◽  
Vol 176 ◽  
pp. 85-94 ◽  
Author(s):  
J.H.M.M. Schmitt

Stellar coronae cannot be spatially resolved, and yet stellar coronae are likely to exhibit a similar amount of structure as the solar corona. Currently, the only way to infer structure from spatially unresolved data is to look for rotational modulation of the X-ray emission or eclipses in the case of binary systems. I will discuss some of the observations obtained and critically review the methods used to infer structure from these data. Particular emphasis will be placed on the ill-conditioned nature of the inversion problem, that makes it next to impossible to infer the possibly three-dimensional structure of stellar coronae.


2019 ◽  
Vol 491 (3) ◽  
pp. 3606-3612 ◽  
Author(s):  
S Ponnada ◽  
M Brorby ◽  
P Kaaret

ABSTRACT The heating of the intergalactic medium in the early, metal-poor Universe may have been partly due to radiation from high-mass X-ray binaries (HMXBs). Previous investigations on the effect of metallicity have used galaxies of different types. To isolate the effects of metallicity on the production of HMXBs, we study a sample consisting only of 46 blue compact dwarf galaxies covering metallicity in the range 12+log(O/H) of 7.15–8.66. To test the hypothesis of metallicity dependence in the X-ray luminosity function (XLF), we fix the XLF form to that found for near-solar metallicity galaxies and use a Bayesian method to constrain the XLF normalization as a function of star formation rate for three different metallicity ranges in our sample. We find an increase by a factor of 4.45 ± 2.04 in the XLF normalization between the metallicity ranges 7.1–7.7 and 8.2–8.66 at a statistical significance of 99.79 per cent. Our results suggest that HMXB production is enhanced at low metallicity, and consequently that HMXBs may have contributed significantly to the reheating of the early Universe.


2006 ◽  
Vol 2 (S235) ◽  
pp. 255-255
Author(s):  
J. M. Vrtilek ◽  
E. J. O'Sullivan ◽  
L. P. David

AbstractChandra and XMM, offering between them high angular resolution, substantial collecting area, and spatially-resolved spectroscopy at good spectral resolution, have given us the means to discover hitherto unanticipated phenomena, in groups as in clusters, and to explore a new set of issues that bring us closer to understanding the formation and evolution of groups and their constituent galaxies: the distribution of heavy elements, the presence of X-ray cavities and their relation to radio observations, the nature of cooling cores, and X-ray signatures of recent galaxy interactions. We here show Chandra and XMM data selected to illustrate recent results regarding some of these themes.


2020 ◽  
Vol 500 (1) ◽  
pp. 215-231
Author(s):  
Ruth A Daly

ABSTRACT Mass accretion rates in dimensionless and physical units, and efficiency factors describing the total radiant luminosity of the disc and the beam power of the outflow are obtained and studied here for samples of black hole systems with outflows. Four samples of sources including 576 LINERs, 100 classical double (FRII) radio sources, 80 relatively local AGN, and 103 measurements of four stellar mass X-ray binary systems, referred to as Galactic Black Holes (GBHs), are included in the study. All of the sources have highly collimated outflows leading to compact radio emission or powerful extended (FRII) radio emission. The properties of each of the full samples are explored, as are those of the four individual GBH, and sub-types of the FRII and local AGN samples. Source types and sub-types that have high, medium, and low values of accretion rates and efficiency factors are identified and studied. A new efficiency factor that describes the relative impact of black hole spin and mass accretion rate on the beam power is defined and studied, and is found to provide a new and interesting diagnostic. Mass accretion rates for 13 sources and efficiency factors for 6 sources are compared with values obtained independently, and indicate that similar values are obtained with independent methods. The mass accretion rates and efficiency factors obtained here substantially increase the number of values available, and improve our understanding of their relationship to source types. The redshift dependence of quantities is presented and the impact on the results is discussed.


2020 ◽  
Vol 498 (2) ◽  
pp. 1651-1667 ◽  
Author(s):  
Antara R Basu-Zych ◽  
Ann E Hornschemeier ◽  
Frank Haberl ◽  
Neven Vulic ◽  
Jörn Wilms ◽  
...  

ABSTRACT eROSITA, launched on 2019 July 13, will be completing the first all-sky survey in the soft and medium X-ray band in nearly three decades. This 4-yr survey, finishing in late 2023, will present a rich legacy for the entire astrophysics community and complement upcoming multiwavelength surveys (with, e.g. the Large Synoptic Survey Telescope and the Dark Energy Survey). Besides the major scientific aim to study active galactic nuclei (AGNs) and galaxy clusters, eROSITAwill contribute significantly to X-ray studies of normal (i.e. not AGN) galaxies. Starting from multiwavelength catalogues, we measure star formation rates and stellar masses for 60 212 galaxies constrained to distances of 50–200 Mpc. We chose this distance range to focus on the relatively unexplored volume outside the local Universe, where galaxies will be largely spatially unresolved and probe a range of X-ray luminosities that overlap with the low luminosity and/or highly obscured AGN population. We use the most recent X-ray scaling relations as well as the on-orbit eROSITA instrument performance to predict the X-ray emission from XRBs and diffuse hot gas and to perform both an analytic prediction and an end-to-end simulation using the mission simulation software, sixte. We consider potential contributions from hidden AGN and comment on the impact of normal galaxies on the measurement of the faint end of the AGN luminosity function. We predict that the eROSITA 4-yr survey, will detect ≳15 000 galaxies (3σ significance) at 50–200 Mpc, which is ∼100 × more normal galaxies than detected in any X-ray survey to date.


1981 ◽  
Vol 93 ◽  
pp. 184-184
Author(s):  
Jean-Pierre De Cuyper

The WR binary systems, consisting of a WR star and an O or B star companion, are supposed to be the progenitors of the massive X-ray binaries. The missing link is generally accepted to be the SN explosion of the WR star which leaves a pulsar remnant. As most pulsars originate from single stars, observations of their proper motions indicate that they receive at their birth a “kick” velocity of about 100 km s−1. We assume this velocity to be due to the asymmetry of the SN explosion. This asymmetry, together with the loss of the SN shell and its impact on the OB star, may cause to disrupt the remaining system.For the ten best known WR binaries we evaluated the survival probability P after an instantaneous SN explosion, leaving a 1.5 M⊙ collapsar with a random orientated kick velocity of 75 kms−1 (case a) and 150 kms−1 (case b) respectively. The influence of the impact is found to be marginal. The run-away velocity of the remaining system and of the disrupted OB star are comparable and of the same order of magnitude, but smaller than the initial orbital velocity of the OB companion; which decreases for increasing values of the initial orbital period. They are found to be independent of the kick velocity.


2015 ◽  
Vol 825-826 ◽  
pp. 814-821 ◽  
Author(s):  
Bernd R. Müller ◽  
Fabien Léonard ◽  
Axel Lange ◽  
Andreas Kupsch ◽  
Giovanni Bruno

X-ray refraction is based on optical deflection of X-rays, similar to the well-known small angle X-ray scattering, but hundreds of times more intense, thus enabling shorter measurement time. We show that X-ray refraction techniques are suitable for the detection of pores, cracks, and in general defects. Indeed, the deflected X-ray intensity is directly proportional to the internal specific surface (i.e., surface per unit volume) of the objects. Although single defects cannot be imaged, the presence of populations of those defects can be detected even if the defects have sizes in the nanometer range.We present several applications of X-ray refraction techniques to composite materials:- To visualize macro and microcracks in Ti-SiC metal matrix composites (MMC);- To correlate fatigue damage (fibre de-bonding) of carbon fibre reinforced plastics (CFRP) to X-ray refraction intensity;- To quantify the impact damage by spatially resolved single fibre de-bonding fraction as a function of impact energy in CFRP laminates.An example of classic high-resolution computer tomography of an impact-damaged CFRP will also be presented, as a benchmark to the present state-of-the-art imaging capabilities. It will be shown that while (absorption) tomography can well visualize and quantify delamination, X-ray refraction techniques directly yield (spatially resolved) quantitative information about fibre de-bonding, inaccessible to absorption tomography.


1982 ◽  
Vol 69 ◽  
pp. 417-443
Author(s):  
Jean-Pierre De Cuyper

AbstractThe effects of an instantaneous asymmetric supernova explosion in an eccentric binary system are analyzed, taking into account the mass loss out of the system, the influence of the impact of the supernova shell on the companion star and the extra “kick” velocity which a collapsed star might receive in an asymmetric supernova explosion. For a random orientat-ion in space of this asymmetric kick velocity, the survival probability and the runaway velocities are derived and their properties discussed for an explosion occurring at a given position in the initial keplerian orbit and the mean and extreme values of these quantities over one orbit are derived. As an example, the outcome of a possible supernova explosion in the ten best known WR+OB binaries is studied and a comparison is made with the observed run-away OB stars, radio pulsars and binary X-ray pulsars.


Author(s):  
R. Beeuwkes ◽  
A. Saubermann ◽  
P. Echlin ◽  
S. Churchill

Fifteen years ago, Hall described clearly the advantages of the thin section approach to biological x-ray microanalysis, and described clearly the ratio method for quantitive analysis in such preparations. In this now classic paper, he also made it clear that the ideal method of sample preparation would involve only freezing and sectioning at low temperature. Subsequently, Hall and his coworkers, as well as others, have applied themselves to the task of direct x-ray microanalysis of frozen sections. To achieve this goal, different methodological approachs have been developed as different groups sought solutions to a common group of technical problems. This report describes some of these problems and indicates the specific approaches and procedures developed by our group in order to overcome them. We acknowledge that the techniques evolved by our group are quite different from earlier approaches to cryomicrotomy and sample handling, hence the title of our paper. However, such departures from tradition have been based upon our attempt to apply basic physical principles to the processes involved. We feel we have demonstrated that such a break with tradition has valuable consequences.


Author(s):  
G. Van Tendeloo ◽  
J. Van Landuyt ◽  
S. Amelinckx

Polytypism has been studied for a number of years and a wide variety of stacking sequences has been detected and analysed. SiC is the prototype material in this respect; see e.g. Electron microscopy under high resolution conditions when combined with x-ray measurements is a very powerful technique to elucidate the correct stacking sequence or to study polytype transformations and deviations from the ideal stacking sequence.


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