scholarly journals Evolution of MAXI J1631–479 during the January 2019 outburst observed by INTEGRAL/IBIS

2020 ◽  
Vol 492 (3) ◽  
pp. 3657-3661 ◽  
Author(s):  
M Fiocchi ◽  
F Onori ◽  
A Bazzano ◽  
A J Bird ◽  
A Bodaghee ◽  
...  
Keyword(s):  
Galactic Plane ◽  
Thermal Emission ◽  
Spectral Characteristics ◽  
Monitoring Program ◽  
High Energy ◽  
Thermal Electron ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Black Hole Candidate ◽  
Decay Times

ABSTRACT We report on a recent bright outburst from the new X-ray binary transient MAXI J1631–479, observed in January 2019. In particular, we present the 30–200 keV analysis of spectral transitions observed with INTEGRAL/IBIS during its Galactic plane monitoring program. In the MAXI and BAT monitoring period, we observed two different spectral transitions between the high/soft and low/hard states. The INTEGRAL spectrum from data taken soon before the second transition is best described by a Comptonized thermal component with a temperature of kTe ∼ 30 keV and a high-luminosity value of $L_{2-200\, \mathrm{keV}}\sim 3\times 10^{38}$ erg−1 (assuming a distance of 8 kpc). During the second transition, the source shows a hard, power-law spectrum. The lack of high energy cut-off indicates that the hard X-ray spectrum from MAXI J1631–479 is due to a non-thermal emission. Inverse Compton scattering of soft X-ray photons from a non-thermal or hybrid thermal/non-thermal electron distribution can explain the observed X-ray spectrum although a contribution to the hard X-ray emission from a jet cannot be determined at this stage. The outburst evolution in the hardness-intensity diagram, the spectral characteristics, and the rise and decay times of the outburst are suggesting that this system is a black hole candidate.

scholarly journals Theoretical Implications of Diffuse Non-Thermal Emission from Clusters of Galaxies

2002 ◽  
Vol 199 ◽  
pp. 141-148
Author(s):  
T.A. Enßlin
Keyword(s):  
Thermal Emission ◽  
Extreme Ultraviolet ◽  
Short Review ◽  
Radio Galaxies ◽  
High Energy ◽  
Clusters Of Galaxies ◽  
Thermal Electron ◽  
Electron Population ◽  
X Ray

A short review on theoretical implications of non-thermal emission (radio, extreme ultraviolet, high energy X-ray) from the intra-cluster medium is given. The origin of cluster radio halos and cluster radio relics is discussed within the framework of a network of processes producing a non-thermal electron population. Emphasis is given to the role of old, remnant, presently invisible relativistic plasma released by former radio galaxies.

scholarly journals Fermi-LAT and WMAP observations of the supernova remnant Puppis A

2013 ◽  
Vol 9 (S296) ◽  
pp. 295-299
Author(s):  
Marie-Hélène Grondin ◽  
John W. Hewitt ◽  
Marianne Lemoine-Goumard ◽  
Thierry Reposeur ◽  
Keyword(s):  
Supernova Remnants ◽  
Supernova Remnant ◽  
Gamma Ray ◽  
High Energy ◽  
Radio Spectrum ◽  
Wilkinson Microwave Anisotropy Probe ◽  
Large Area ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Γ Ray

AbstractThe supernova remnant (SNR) Puppis A (aka G260.4-3.4) is a middle-aged supernova remnant, which displays increasing X-ray surface brightness from West to East corresponding to an increasing density of the ambient interstellar medium at the Eastern and Northern shell. The dense IR photon field and the high ambient density around the remnant make it an ideal case to study in γ-rays. Gamma-ray studies based on three years of observations with the Large Area Telescope (LAT) aboard Fermi have revealed the high energy gamma-ray emission from SNR Puppis A. The γ-ray emission from the remnant is spatially extended, and nicely matches the radio and X-ray morphologies. Its γ-ray spectrum is well described by a simple power law with an index of ~2.1, and it is among the faintest supernova remnants yet detected at GeV energies. To constrain the relativistic electron population, seven years of Wilkinson Microwave Anisotropy Probe (WMAP) data were also analyzed, and enabled to extend the radio spectrum up to 93 GHz. The results obtained in the radio and γ-ray domains are described in detail, as well as the possible origins of the high energy γ-ray emission (Bremsstrahlung, Inverse Compton scattering by electrons or decay of neutral pions produced by proton interactions).

scholarly journals Nonthermal processes in microquasars

2010 ◽  
Vol 6 (S275) ◽  
pp. 215-223
Author(s):  
Valentí Bosch-Ramon
Keyword(s):  
Thermal Emission ◽  
High Energy ◽  
Energy Bands ◽  
X Ray ◽  
Radio Jets ◽  
Extended Radio ◽  
Very High Energy ◽  
X Ray Binaries ◽  
Very High ◽  
Negligible Contribution

AbstractMicroquasars are X-ray binaries that show extended radio jets. These jets can accelerate particles up to relativistic energies that produce non-thermal emission from radio to TeV, and could also make a non-negligible contribution to the galactic CRs in some energy ranges. The orbital motion and compactness of these sources allow the study of high-energy astrophysical phenomena in extreme conditions that change in accessible timescales. In this work, I briefly discuss the production of broadband non-thermal emission in microquasars, putting special emphasis on the high- and the very high-energy bands.

scholarly journals Multiwavelength Temporal Behavior of GRS 1915+105

1998 ◽  
Vol 188 ◽  
pp. 396-397
Author(s):  
D. Hannikainen ◽  
Ph. Durouchoux
Keyword(s):  
Galactic Plane ◽  
Compact Object ◽  
Optical Counterpart ◽  
High Luminosity ◽  
Relativistic Jets ◽  
X Ray ◽  
Black Hole Candidate ◽  
Superluminal Motion ◽  
Extreme Variability ◽  
Sky Monitor

The transient X-ray source GRS 1915+105 was discovered in August 1992 with the GRANAT/WATCH all-sky monitor (Castro-Tirado et al. 1994). Subsequent VLA observations from March through April 1994 led to the discovery of apparent superluminal motion in a pair of radio condensations moving away from the compact radio core (Mirabel & Rodriguez 1994). These jet-like features are interpreted as a bipolar outflow with bulk velocity ~ 0.9c. Although no optical counterpart has been observed, due to the heavy extinction in the Galactic plane, and therefore not enabling measurements of the mass of the compact object, the hard X-ray spectrum and high luminosity (~ 1039 erg s−1), extreme variability in the X-ray light curve and the relativistic jets make GRS 1915+105 a strong black hole candidate.

scholarly journals Deep X-ray view of the Class I YSO Elias 29 with XMM-Newton and NuSTAR

2019 ◽  
Vol 623 ◽  
pp. A67 ◽  
Author(s):  
I. Pillitteri ◽  
S. Sciortino ◽  
F. Reale ◽  
G. Micela ◽  
C. Argiroffi ◽  
...  
Keyword(s):  
Thermal Emission ◽  
Total Duration ◽  
Circumstellar Disks ◽  
High Energy ◽  
Class I ◽  
Young Stellar Objects ◽  
X Rays ◽  
Coronal Emission ◽  
Compact Structure ◽  
X Ray

X-ray emission is a characteristic feature of young stellar objects (YSOs) and the result of the interplay between rotation, magnetism, and accretion. For this reason high energy phenomena are key elements to understand the process of star formation, the evolution of their circumstellar disks, and eventually the formation of planets. We investigated the X-ray characteristics of the Class I YSO Elias 29 with joint XMM-Newton and NuSTAR observations of total duration 300 ks and 450 ks, respectively. These are the first observations of a very young (<1 Myr) stellar object in a band encompassing simultaneously both soft and hard X-rays (0.3 − 10 keV in XMM-Newton and ≈3 − 80 keV in NuSTAR). The quiescent spectrum is well described by one thermal component at ∼4.2 keV absorbed by NH ∼ 5.5  ×  1022 cm−2. In addition to the hot Fe complex at 6.7 keV, we observed fluorescent emission from Fe at ∼6.4 keV, confirming the previous findings. The line at 6.4 keV is detected during quiescent and flaring states and its flux is variable. The equivalent width is found varying in the range ≈0.15 − 0.5 keV. These values make unrealistic a simple model with a centrally illuminated disk and suggest a role of the cavity containing Elias 29 and possible reverberation processes that could occur in it. We observed two flares that have durations of 20 ks and 50 ks, respectively, and we observed the first flare with both XMM-Newton and NuSTAR. For this flare, we used its peak temperature and timing as diagnostics to infer a loop size of about 1 − 2 R⊙ in length, which is about 20%–30% of the stellar radius. This implies a relatively compact structure. We systematically observed an increase in NH of a factor five during the flares. This behavior has been observed during flares previously detected in Elias 29 with XMM-Newton and ASCA. The phenomenon suggests that the flaring regions could be buried under the accretion streams and at high stellar latitudes because the X-rays from flares pass through gas denser than the gas along the line of sight of the quiescent corona. In a different scenario, a contribution from scattered soft photons to the primary coronal emission could mimic a shallower NH in the quiescent spectrum. In the spectrum of the full NuSTAR exposure, we detect hard X-ray emission in the band ≈20 − 80 keV which is in excess with respect to the thermal emission and that is significant at a level of ≥2σ. We speculate that the hard X-ray emission could be due to a population of energetic electrons accelerated by the magnetic field along the accretion streams. These particles, along with X-ray photons with E >  7.11 keV, could be responsible for pumping up the Fe fluorescence when hitting cold Fe in the circumstellar disk.

scholarly journals Magnetic Reconnection as the Origin of Galactic Ridge X-Ray Emission

1998 ◽  
Vol 188 ◽  
pp. 269-270 ◽  
Author(s):  
S. Tanuma ◽  
T. Yokoyama ◽  
T. Kudoh ◽  
K. Shibata ◽  
R. Matsumoto ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Magnetic Reconnection ◽  
Galactic Plane ◽  
Thermal Emission ◽  
Mhd Equations ◽  
Magnetic Islands ◽  
Cool Component ◽  
X Ray ◽  
Hot Plasma ◽  
Helical Tubes

We present a scenario for the origin of the hot plasma in our Galaxy, as a model of a strong X-ray emission (LX(2 – 10keV) ~ 1038 erg s−1), called Galactic Ridge X-ray Emission (GRXE), which has been observed near the Galactic plane. GRXE is thermal emission from hot component (~ 7 keV) and cool component (~ 0.8 keV). Observations suggest that the hot component is diffuse, and is not escaping away freely. Both what heats the hot component and what confines it in the Galactic ridge are still remained puzzling, while the cool component is believed to be made by supernovae. We propose a new scenario: the hot component of GRXE plasma is heated by magnetic reconnection, and confined in the helical magnetic field produced by magnetic reconnection or in the current sheet and magnetic field. We solved also the 2-dimensional magnetohydrodynamic (MHD) equations numerically to study how the magnetic reconnection creates hot plasmas and magnetic islands (helical tubes), and how the magnetic islands confine the hot plasmas in Galaxy. We conclude that the magnetic reconnection is able to heat up the cool component to hot component of GRXE plasma if the magnetic field is localized into intense flux tube with Blocal ~ 30 μG (the volume filling factor of f ~ 0.1).

scholarly journals Starburst and post-starburst high-redshift protogalaxies

2019 ◽  
Vol 626 ◽  
pp. A85 ◽  
Author(s):  
Ellis R. Owen ◽  
Kinwah Wu ◽  
Xiangyu Jin ◽  
Pooja Surajbali ◽  
Noriko Kataoka
Keyword(s):  
Star Formation ◽  
High Redshift ◽  
High Energy ◽  
Starburst Galaxies ◽  
X Rays ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
High Energy Cosmic Rays ◽  
Radiation Fields ◽  
Inverse Compton

Quenching of star-formation has been identified in many starburst and post-starburst galaxies, indicating burst-like star-formation histories (SFH) in the primordial Universe. Galaxies undergoing violent episodes of star-formation are expected to be rich in high energy cosmic rays (CRs). We have investigated the role of these CRs in such environments, particularly how they could contribute to this burst-like SFH via quenching and feedback. These high energy particles interact with the baryon and radiation fields of their host via hadronic processes to produce secondary leptons. The secondary particles then also interact with ambient radiation fields to generate X-rays through inverse-Compton scattering. In addition, they can thermalise directly with the semi-ionised medium via Coulomb processes. Heating at a rate of ∼10−25 erg cm−3 s−1can be attained by Coulomb processes in a star-forming galaxy with one core-collapse SN event per decade, and this is sufficient to cause quenching of star-formation. At high-redshift, a substantial amount of CR secondary electron energy can be diverted into inverse-Compton X-ray emission. This yields an X-ray luminosity of above 1041 erg s−1by redshiftz = 7 which drives a further heating effect, operating over larger scales. This would be able to halt inflowing cold gas filaments, strangulating subsequent star-formation. We selected a sample of 16 starburst and post-starburst galaxies at 7 ≲ z ≲ 9 and determine the star-formation rates they could have sustained. We applied a model with CR injection, propagation and heating to calculate energy deposition rates in these 16 sources. Our calculations show that CR feedback cannot be neglected as it has the strength to suppress star-formation in these systems. We also show that their currently observed quiescence is consistent with the suffocation of cold inflows, probably by a combination of X-ray and CR heating.

scholarly journals A tale of two shocks in SN 2004dj

2013 ◽  
Vol 9 (S296) ◽  
pp. 108-111
Author(s):  
Alak Ray ◽  
Sayan Chakraborti ◽  
Naveen Yadav ◽  
Randall Smith ◽  
Poonam Chandra ◽  
...  
Keyword(s):  
Thermal Emission ◽  
Mass Loss Rate ◽  
Circumstellar Matter ◽  
Published Data ◽  
Reverse Shock ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Field Amplification ◽  
Forward Shock ◽  
Red Supergiants

AbstractType IIP SNe constitute a major fraction of all core-collapse supernovae and arise from massive stars that end their lives close to Red Supergiants. The blastwave from the SN interacting with the progenitor's circumstellar matter produces a hot region bounded by a forward and a reverse shock from which most of the X-ray emission originates. Analysis of archival Chandra observations of SN 2004dj, one of the nearest supernovae since SN 1987A, together with published data from radio and optical bands determines the pre-explosion mass-loss rate, blastwave speed, electron acceleration and magnetic field amplification efficiencies. X-ray emission arises from both inverse Compton scattering by non-thermal electrons accelerated in the forward shock and from thermal emission from the supernova ejecta hit by the reverse shock. Determination of the properties of the radiating plasma based on the separation of thermal and non-thermal radiation differentiates different types of supernovae and their environments.

scholarly journals Non thermal emission from T Tauri stars

2010 ◽  
Vol 6 (S275) ◽  
pp. 404-405
Author(s):  
María V. del Valle ◽  
Gustavo E. Romero
Keyword(s):  
Main Sequence ◽  
Thermal Emission ◽  
High Energy ◽  
Magnetic Activity ◽  
T Tauri Stars ◽  
Main Sequence Stars ◽  
High Energy Radiation ◽  
X Ray ◽  
T Tauri ◽  
Low Mass

AbstractT Tauri stars are low mass, pre-main sequence stars. These objects are surrounded by an accretion disk and present strong magnetic activity. T Tauri stars are copious emitters of X-ray emission which belong to powerful magnetic reconnection events. Strong magnetospheric shocks are likely outcome of massive reconnection. Such shocks can accelerate particles up to relativistic energies through Fermi mechanism. We present a model for the high-energy radiation produced in the environment of T Tauri stars. We aim at determining whether this emission is detectable. If so, the T Tauri stars should be very nearby.

scholarly journals Inverse-Compton scattering in the resolved jet of the high-redshift quasar PKS J1421−0643

2020 ◽  
Vol 497 (1) ◽  
pp. 988-1000 ◽  
Author(s):  
D M Worrall ◽  
M Birkinshaw ◽  
H L Marshall ◽  
D A Schwartz ◽  
A Siemiginowska ◽  
...  
Keyword(s):  
Gamma Ray ◽  
High Redshift ◽  
Lorentz Factor ◽  
High Energy ◽  
Radio Spectrum ◽  
X Rays ◽  
X Ray ◽  
Inverse Compton Scattering ◽  
Inverse Compton ◽  
Jet Power

ABSTRACT Despite the fact that kpc-scale inverse-Compton (iC) scattering of cosmic microwave background (CMB) photons into the X-ray band is mandated, proof of detection in resolved quasar jets is often insecure. High redshift provides favourable conditions due to the increased energy density of the CMB, and it allows constraints to be placed on the radio synchrotron-emitting electron component at high energies that are otherwise inaccessible. We present new X-ray, optical, and radio results from Chandra, HST, and the VLA for the core and resolved jet in the z = 3.69 quasar PKS J1421−0643. The X-ray jet extends for about 4.5 arcsec (32 kpc projected length). The jet’s radio spectrum is abnormally steep and consistent with electrons being accelerated to a maximum Lorentz factor of about 5000. Results argue in favour of the detection of iC X-rays for modest magnetic field strength of a few nT, Doppler factor of about 4, and viewing angle of about 15°, and predict the jet to be largely invisible in most other spectral bands including the far- and mid-infrared and high-energy gamma-ray. The jet power is estimated to be about 3 × 1046 erg s−1 which is of order a tenth of the quasar bolometric power, for an electron–positron jet. The jet radiative power is only about 0.07 per cent of the jet power, with a smaller radiated power ratio if the jet contains heavy particles, so most of the jet power is available for heating the intergalactic medium.

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