Posters
Posters
Halim Ashkar ** Searches for TeV gamma-ray counterparts to Gravitational Wave events with H.E.S.S.
J. Michael Burgess ** 3ML: The Multi-Mission Maximum Likelihood Framework
Zhi Chang ** Multi Messengers to gamma-ray Binary
Jerome Chenevez ** A search for X-ray burst thermonuclear burning ashes with NICER
Remi Chipaux ** HEART : Athena Exacrad program, work package 4
Alessandra Costantino ** Constructing an IBIS/ISGRI slew survey
Marta Dzielak ** Comparison of spectral models for disc truncation in the hard state of GX 339-4
Alexandros Filothodoros ** A long term hard X-ray analysis of GRS 1758-258 using INTEGRAL data.
Lingsong Ge ** Bayesian Hierarchical Method of AGN X-ray Spectral Fitting
Katerina Goluchova ** Power density spectra of modes of orbital motion in strongly curved space-time: obtaining the observable signal
Aleksandra Gros ** Analysis of the IBIS/ISGRI systematic source location offsets
Jessymol K Thomas ** "MAXI J 1820+070: A new black hole low-mass X-ray binary candidate."""
Shigeyuki Karino ** Evolution of wind-fed High Mass X-ray Binaries
Debora Lancova ** Global GRRMHD simulation of thin accretion disc stabilized by magnetic field
Philippe Laurent ** XGRE: a TGF/GRB detector on the TARANIS space mission
Niels Lund ** Special features in JEM-X OSA-11
Fiona Helen Panther ** Positron moderation by silicon carbide dust grains
Aymeric Sauvageon ** ISGRI: background evolution and noisy pixel handling
Celia Sanchez Fernandez ** The clock wagging its tail:INTEGRAL detection of X-ray burst-induced coronal cooling in GS 1826-24
Stephane Schanne ** The SVOM/ECLAIRs Gamma-Ray Burst Trigger
Andy Shearer ** Gamma-ray and Optical Polarimetric Observations of the Crab Pulsar and nebula using Integral and GASP.
Agnieszka Szelecka ** Spectral states of NGC 4151 observed with INTEGRAL
Henri Triou ** Scientific Performances of the ECLAIRs space telescope within the SVOM mission
Mariusz Tarnopolski ** Analysis of the duration-hardness ratio plane of gamma-ray bursts using skewed distributions
Gabriela Urbancova ** Properties of the Hartle-Thorne epicyclic oscillations
Martin Urbanec ** Constraining neutron star equation of state from X-ray observations
Alessandro Ursi ** Detection of short GRBs and sub-threshold events with the AGILE MCAL
Armin Vahdat Motlagh ** Investigating state transition luminosities of Galactic black hole transients in the outburst decay
Janusz Ziolkowski ** The effect of the illumination on the evolution of the binary system V821 Ara/GX 339-4
Andrea Tramacere ** JetSeT a framework for self-consistent modeling and fitting of astrophysical relativistic jets
In multi-messenger astronomy we search for electromagnetic counterparts for gravitational waves events. One of these searches is the one for high energy gamma-ray emission with the H.E.S.S. Imaging Air Cherenkov Telescopes in Namibia. During their second Observation Run O2, the Advanced VIRGO detector in Italy and the two advanced LIGO detectors in Washington and Louisiana observed, simultaneously for the first time, on August 14 2017 a transient gravitational wave signal due to the coalescence of two stellar masses black holes, an event labeled GW170814. The alert announcing the event was issued two hours later and H.E.S.S. observations could be scheduled for the nights of 16, 17 and 18 August 2017. Three days after the binary BH merger, on August 17, the coalescence of two neutron star was detected for the first time, followed by a GRB detection by Fermi's GBM starting a new era in Multi-messenger Astronomy. Observations started 5.3 h after the merger and contained the counterpart SSS17a that was identified several hours later. It stands as the first data obtained by a ground-based pointing instrument on this object. In this contribution, we will present the results of the search of high-energy gamma ray emission as electromagnetic counterpart of these two GW events. No significant gamma ray emission was detected for either event. But for the first time upper limit maps were derived constraining the non-thermal, high-energy emission following a three detector binary black hole coalescence (GW170814), and a binary neutron star coalescence (GW170817).
J. Michael Burgess ** 3ML: The Multi-Mission Maximum Likelihood Framework
We present 3ML, an abstract data interface and analysis tool for multi-messenger data. 3ML allows for users to analyze data from different instruments together with their native data interfaces naturally increasing the sensitivity of each instrument and allowing them to interact with models via the appropriate likelihoods. We also show the current development of pySPI, a python replacement for SPIMODFIT that provides an interface to 3ML.
Zhi Chang ** Multi Messengers to gamma-ray Binary
Gamma-ray binaries are a special class of X-ray binaries. They emit high-energy gamma radiation at TeV and/or GeV energies and consist of a compact object (neutron star or black hole, unknown except for PSR B1259-63) and a high-mass O/B star. LS 5039 and PSR B1259-63 are two of such system. For LS 5039, we investigate its multi-wavelength emission. The orbital light curve peak is moving with the variability of energy band, and it has some connections with its SED. The pulsar wind collision model is supported with our results. PSR B1259-63 is the only system that the nature of the object is known as a pulsar. Gamma-ray flare events were found during its periastron passages with Fermi-LAT observations. The features of each flare are different with each other, and delays were found compared with X-ray observation. These challenge the previous models used to interpreting its radiation.
Jerome Chenevez ** A search for X-ray burst thermonuclear burning ashes with NICER
Thermonuclear bursts on the surface of accreting neutron stars reach sometimes luminosities that can temporarily exceed the Eddington limit and drive the photosphere to large radii. Such photospheric radius expansion bursts may eject nuclear burning ashes that are expected to engender absorption features in the burst spectra. Simultaneous detections in NICER spectra of multiple photoionization edges from heavy elements will probe the thermonuclear burning and mixing processes under degenerate conditions. Moreover, the identification of gravitationally-redshifted edges would uniquely provide a measure of the neutron star compactness, and thus constitute a probe of the ultra-dense matter equation of state.
Remi Chipaux ** HEART : Athena Exacrad program, work package 4
The objective of the ATHENA Exacrad program is to quantify the physical models and cross sections for high-energy charged particle secondary production in representative spacecraft and instrument materials, together with evaluation of low-energy charged particle forward scattered in the ATHENA mirror, using accelerator facilities. This shall allow improved evaluation of radiation-induced background on ATHENA science data. Among the five defined work packages, WP4 is devoted to the measure of secondary particles induced by high-energy protons. It will use the 250 MeV beam of the Proton Irradiation Facility at the Paul Scherrer Institut in Villigen (CH). The experimental setup is composed of several stacked components, namely a gas detector to measure low energy electrons, a plastic scintillator to discriminate charged particles from photons and a BGO crystal to measure high-energy electrons and photons. We will also present initial Geant4 simulations of the test. On behalf of the WP4 team: Philippe Laurent, David Attie, Remi Chipaux, Esther Ferrer-Ribas, CEA/DRF/Irfu, Saclay, France Isabelle Deloncle, Jurgen Kiener, Vincent Tatischeff, CNRS/IN2P3/CSNSM, Orsay, France
Alessandra Costantino ** Constructing an IBIS/ISGRI slew survey
This work aims at producing a slew survey" with data from the IBIS imager on board the INTEGRAL satellite. INTEGRAL observations consist of a series of pointed exposures which last usually a few ks. The detector image (shad- owgram) is then processed to obtain scientific data. Each revolution of the INTEGRAL spacecraft consists of [?] 200 ks of pointing observations and 15 ks of slew observations, which means slews contribute to [?] 7.5% of the total ob- serving time. While slewing from one pointing to the next, the direction of the telescope's axis changes continuously, a shadowgram can not be made, and the usual processing method can not be applied. An alternative approach, based on a back projection technique, is used in this work to process these data for the first time. Access to the slew data taken during the whole mission will provide a total of [?] 30 Ms ([?] 150 orbits) of extra data. A sensitivity limit of [?] 50 - 70 mCrabs is estimated for a single slew, depending on how fast the pointing axis is moving, and hence the total amount of time that a source stays in the field of view during the scan. Slew data will e used to supplement existing light curves for known sources, and to search for new transient detections."
Marta Dzielak ** Comparison of spectral models for disc truncation in the hard state of GX 339-4
We probe models of disc truncation in the hard spectral state of an outburst of the X-ray transient GX 339-4. We test a large number of different models of disc reflection and its relativistic broadening, using two independent sets of codes. We apply it to a Rossi X-ray Timing Explorer spectrum in the rising part of the hard state. Our statistically best model has a physical thermal Comptonization primary continuum, requires the disc to be truncated at a radius larger than that of >2 ISCO, and predicts a disc inclination in agreement with that of the binary. A paper presenting our results has been submitted to MNRAS (arXiv:1811.09145). We acknowledge funding from the European Union's Horizon 2020 Programme under the AHEAD project (grant agreement n. 654215).
Alexandros Filothodoros ** A long term hard X-ray analysis of GRS 1758-258 using INTEGRAL data.
We present preliminary results of our study of the black hole binary GRS 1758-258 emission, using all the publicly available INTEGRAL data, spanning a period of 16 years. To classify the spectral states of the source we applied a power-law model in order to estimate the 22 -- 100 keV flux and photon index for each spacecraft orbit. Using these results we have prepared four spectral sets, using ISGRI, JEMX and PICsIT spectra, corresponding to four ranges of the hard X-ray flux. These sets were analyzed with a hybrid Comptonization model, allowing to study a variation of several physical parameters of the system when its brightness changes in a broad range. The results are interpreted in a context of the physics of the persistent and transient black hole binaries.
Lingsong Ge ** Bayesian Hierarchical Method of AGN X-ray Spectral Fitting
We present a Bayesian hierarchical method (BHM) to fit active galactic nuclei (AGN) spectra in the X-ray band from 0.3 keV to around 10 keV with a physical model. The AGN X-ray spectra are very complex and show many different characteristics depending on the objects. Such spectra are therefore usually fitted manually with models chosen on case-by-case basis. However, this approach has two problems: Firstly, it is not feasible for a survey with a large number of sources. Secondly, in the case of low S/N ratio, there is tendency to adopt a model which is too simple, making the uncertainties on the parameters quite unrealistic. Therefore a relatively comprehensive model and automatic fitting method are required. With the BHM we are capable of fitting the AGN spectra automatically with a single model which is physically motivated. Also, using strong priors derived from deep observations we show that we are able to determine the most relevant spectral parameters, e.g. photon index and hydrogen column density, without bias even at low S/N ratio, though in this case we cannot constrain parameters of secondary emissions like the soft excess and scattering due to the low quality of data. We show examples of fitting for a few sources with this automatic BHM.
Katerina Goluchova ** Power density spectra of modes of orbital motion in strongly curved space-time: obtaining the observable signal
We explore the appearance of an observable signal generated by accretion tori and small radiating circular hot spots moving along quasi-elliptic trajectories close to the innermost stable circular orbit in the Schwarzschild spacetime. Our consideration takes into account the capabilities of observatories that have been operating in the past two decades represented by the Rossi X-ray Timing Explorer (RXTE) and the proposed future instruments. We conclude that the ability to recognize the harmonic content of the signal can help to distinguish between the different proposed physical models.
Aleksandra Gros ** Analysis of the IBIS/ISGRI systematic source location offsets
Source positions provided by the standard OSA software from the INTEGRAL IBIS/ISGRI data are corrected using a model based on measures of IBIS mask temperature. We investigated the residual biases still present for strong sources by analysing a large number of observations covering more than ten years of the mission. We found a clear dependence on the satellite roll angle that can be reduced by independent modelling of the IBIS mask quarter displacements and taking into account the photon penetration effect in the ISGRI detector pixels. Preliminary results are presented for strong sources. However, further work is needed to improve the telescope modelling and refine the source location offset correction.
Jessymol K Thomas ** "MAXI J 1820+070: A new black hole low-mass X-ray binary candidate."""
MAXI J1820+070, a new bright X-ray transient source, has been observed by a number of telescopes since its discovery on 11 March 2018. Based on multiwavelength observations, MAXI J1820+070 has been identified as a new black hole candidate low-mass X-ray binary. Our high-speed photometry undertaken with the SHOC CCD camera on the SAAO 1-m telescopes, plus SALT slotmode observations, reveals high frequency variability in the frequency range ~0.01- 0.2 Hz. In addition we have obtained SALT spectra of the source which shows strong emission lines (Balmer series, HeII and [C III]/[N III]), which are clearly modulated on the proposed 17 h orbital period. These observations strongly support the black hole X-ray binary classification, as does it transitioned from a hard-to-soft X-ray state in July 2018. Recently it has declined in brightness following the soft-to-hard transition.
Shigeyuki Karino ** Evolution of wind-fed High Mass X-ray Binaries
The evolution tracks of high mass X-ray binaries involving neutron stars are considered. We have constructed a binary evolution code which includes the evolution of NS magnetic field and spin. With this code, we investigate the mass transfer rate from the donor to the NS via stellar wind, and trace the resultant evolution of binary parameters. In this binary evolution computation, we consider the exact amount of mass and angular momentum transfer rate from the donor wind, without adopting the Hoyle-Littleton model. We identify the propeller regime and study the lifelong variations of X-ray luminosities of HMXBs. Then we discuss the observable duration of persistent XBPs, SFXTs and PULXs.
Debora Lancova ** Global GRRMHD simulation of thin accretion disc stabilized by magnetic field
We analyse the properties of a geometrically thin and optically thick accretion disc which is stabilized by magnetic field. For simulation purpose we use GRMHD code Koral. The thin disc solution was published in Sadowski 2016 and we are using these results for deeper analysis. We extended the results presented in Sadowski 2016 by conducting the simulations for more initial parameters. The key parameters we analyze are the stresses on the inner edge of the disc and the effective viscous parameter a_eff for a thin accretion disc stabilized by magnetic field.
Philippe Laurent ** XGRE: a TGF/GRB detector on the TARANIS space mission
In this poster, we will present the French TARANIS micro-satellite dedicated to the study of thunderstorm and Terrestrial Gamma-Ray Flashes. The TARANIS gamma-ray instrument, XGRE, with an unprecedented timing resolution in this energy range, will also detect GRB and bright x-ray sources, such as the Crab and Cygnus X-1. We will present also XGRE characteristics and its capacity to measure celestial sources.
Niels Lund ** Special features in JEM-X OSA-11
The new release of the Observation Standard Analysis package (OSA-11) contains an updated version of the JEM-X analysis software. This version enables the j_ima_iros package to produce light curves making use of the more detailed understanding of the JEM-X instrument behahiour than was available in the earlier light curve extraction software. The new light curves will be output in special files (jmxN_src_iros_lc.fits) using the same standard data format as the previous light curve files (jmxN_src_lc.fits). A new feature is the ability to perform an automatic detection of bursts in the light curves. If bursts are detected this will be indicated in the flag-word in the jmxN_srcl_res.fits-files. Additional burst details can be output in non-standard formats by adding special keywords in the science analysis set-up. The content and usage of this non-standard feature will be described.
Fiona Helen Panther ** Positron moderation by silicon carbide dust grains
For 50 years, positron annihilation has been observed in the Milky Way Galaxy. The origin of these positrons remains unknown, however one plausible source of a fraction of the annihilating positrons is through the decay of radioactive material produced in supernova explosions. These cataclysmic events can also synthesize large quantities of dust, in which positron-producing nuclei may be embedded. We investigate the impact of positron implantation in silicon carbide dust grains produced in core collapse supernova on the initial kinetic energy distribution of positrons produced by supernovae.
Aymeric Sauvageon ** ISGRI: background evolution and noisy pixel handling
It presents the background dominated by cosmic rays and the efficient on-board rejection of unwanted events (with IBIS filtering and ISGRI noisy pixel handling).
Celia Sanchez Fernandez ** The clock wagging its tail:INTEGRAL detection of X-ray burst-induced coronal cooling in GS 1826-24
In the hot flow paradigm of accreting Low Mass X-ray Binaries, the inner accretion disk is replaced by a hot inner flow which cools by Compton up-scattering low energy photons. In NS systems, these seed photons proceed from the truncated thin disc, the heated NS surface, and possibly synchrotron emission within the hot flow. During an X-ray burst, the number of seed photons that enter the hot flow increase dramatically during an X-ray bursts. It is therefore expected that the electron temperature will drop during the bursts and the Comptonized spectrum will soften from the persistent level. We have analysed the available INTEGRAL data on the 'clocked burster', GS 1826-24. We have studied its overall evolution over 14 years on INTEGRAL observations. From these data, we have selected a homogeneous sample of 48 X-ray bursts detected in the hard state. By stacking the JEM-X and ISGRI spectra of these bursts, we have studied the spectral evolution of the burst hard X-ray emission, and for the first time, studied the variation of the hot flow electron temperatures as the burst proceeds. We present here the results of this analysis.
Stephane Schanne ** The SVOM/ECLAIRs Gamma-Ray Burst Trigger
SVOM, the Space-based multi-band astronomical Variable Objects Monitor, is a Chinese-French satellite mission devoted to Gamma-Ray Bursts (GRBs), currently in Phase C, with a launch foreseen end of 2021. SVOM will study GRBs in a wide spectral range thanks to its 4 on-board as well as ground-based instruments. The instrument ECLAIRs onboard SVOM, a coded-mask soft gamma-ray camera observing in the 4-150 keV energy band with a 2 sr large field of view, will detect the GRBs of the mission. The ECLAIRs onboard Management and Scientific Trigger Unit (UGTS) analyzes the real-time data, in order to detect and localize the GRBs, to request the spacecraft slew for GRB follow-up observations by the other onboard instruments (MXT in X-rays and VT in the visible), and to alert the ground observers. This paper presents the ECLAIRs Trigger system.
Andy Shearer ** Gamma-ray and Optical Polarimetric Observations of the Crab Pulsar and nebula using Integral and GASP.
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Agnieszka Szelecka ** Spectral states of NGC 4151 observed with INTEGRAL
The brightest Seyfert 1 Galaxy NGC 4151 was observed by INTEGRAL in years 2003-2015, showing the hard X-ray emission varying in a broad range. Thanks to a relatively high quality of the INTEGRAL/ISGRI spectra, accompanied by spectra collected with several soft X-ray satellites, we analyzed properties of four flux states of the system with physical models including thermal Comptonization. Obtained results, together with various correlations, are discussed in a framework of the common and distinct physics of active galactic nuclei and black hole binaries.
Henri Triou ** Scientific Performances of the ECLAIRs space telescope within the SVOM mission
SVOM is a French-Chinese space mission to be launched in 2021, which goal is to perform multi-wavelength analysis of transient events in the sky, among which Gamma-Ray Bursts, the most powerful stellar explosions in the Universe . SVOM aims to be the next Gamma-Ray Bursts multi wavelength space observatory. The ECLAIRs space telescope is part of the French contribution on the SVOM mission. By detecting the very first lights (prompt emission) of the Gamma Ray Bursts in the [4 keV - 150 keV] energy range, ECLAIRs will be the initiator of the follow-up (multivawelength observations) based on a complementary network of space and ground instruments. The scientific performance of the ECLAIRs instrument and its design are deduced from the scientific objectives allocated to ECLAIRs within the SVOM mission. The architecture is based on a combination of 3 key solutions: the coded mask imaging associated with advanced imaging software, a compact ASIC-CdTe hybrid detector with low noise/low energy level threshold (4 keV) as well as high sensitivity and an onboard powerful processor along with its associated trigger algorithms for gamma ray bursts detection. Each of ECLAIRs subsystems have therefore needed specific system performance analysis and simulators developments in order to reach optimized solutions allowing the ECLAIRs system to meet the expected scientific performances. We present the performance system analysis at mission and instrument levels. We also detail the main scientific performance (sensitivity, localization accuracy, energy resolution ...) ofthe ECLAIRs instrument together with the tools developed to validate these performances at system and subsystem levels.
Mariusz Tarnopolski ** Analysis of the duration-hardness ratio plane of gamma-ray bursts using skewed distributions
The two widely accepted classes of gamma-ray bursts (GRBs), short and long, are with confidence ascribed to mergers of compact objects and collapse of massive stars, respectively. A third, intermediate/soft class, remains putative. Its existence was claimed based on univariate and bivariate analyses of GRB observables modeled with Gaussian distributions. This, however, may not be the appropriate approach, as it has been already shown that the univariate distributions of durations are better described by mixtures of two skewed components rather than three Gaussian ones. This paper investigates whether data in the duration--hardness ratio plane is better modeled by mixtures of skewed bivariate distributions than by normal ones. The archival data set of the {\it Compton Gamma-Ray Observatory}/BATSE and {\it Fermi}/GBM data from the most recent catalogue release are examined. The preferred model is chosen based on two information criteria, Akaike ($AIC$) and Bayesian ($BIC$). It is found that the best description is given by a two-component mixture of skewed Student-$t$ distributions, which outperforms any other model considered. This implies that the distribution of the studied parameters is intrinsically skewed, introducing spurious Gaussian components, and hence the third class is unlikely to be a real phenomenon. Its existence, based on statistical inference, is therefore rejected as unnecessary to explain the observations.
Gabriela Urbancova ** Properties of the Hartle-Thorne epicyclic oscillations
We will present a detailed analysis of the properties of the frequencies of the radial and the vertical epicyclic motion and the frequency of the orbital motion in the Hartle- Thorne geometry. This metric is characterised by gravitational mass M, angular momentum J and quadrupole moment Q. By this geometry is properly described the external spacetime of slowly rotating stars in general relativity. Our investigation is motivated by X-ray observations of binary systems containing a rotating compact star accreting matter from its binary companion. In such systems, twin high-frequency quasi-periodic oscillations are observed with a frequency ratio approaching 3 : 2 or even 5 : 4. These twin oscillations can be explained by models using orbital and epicyclic frequencies of quasi-circular geodesic motion.
Martin Urbanec ** Constraining neutron star equation of state from X-ray observations
X-ray missions provide a unique tool to observe neutron stars and to estimate their properties. These are governed by the behavior of matter under extreme conditions found in the interiors of neutron stars and being described by the equation of state. In the presentation, we will shortly overview current possibilities how to constrain equations of state and we will particularly focus on observations of quasi-periodic oscillations detected in power density spectra of low mass X-ray binaries.
Alessandro Ursi ** Detection of short GRBs and sub-threshold events with the AGILE MCAL
The MiniCALorimeter (MCAL) on-board the Astrorivelatore Gamma ad Immagini LEggero (AGILE) is a non-imaging, all-sky detector, sensitive in the 0.4-100 MeV energy range. Since August 2016, it was put in the so-called "MCAL-GW"" configuration, which consists of a substantial improvement of the on-board trigger capabilities, for the detection of short duration high-energy transients, such as Short Gamma-Ray Bursts (SGRBs) and weak gamma-ray Sub-Theshold Events (STEs). Aim of this new configuration is to make AGILE more competitive in the detection of possible electromagnetic counterparts to Gravitational Wave (GW) events, revealed by the LIGO/Virgo experiments in the forthcoming O3 run, starting in early 2019. From August 2016 to May 2018, the new adopted ""MCAL-GW"" configuration enhanced the number of MCAL on-board triggers, increasing the total detector acquisition time, and leading to the detection of tens of bursts, confirmed by the InterPlanetary Network (IPN). Moreover, in the same period, thousands of STEs have been identified, although the real physical nature of these events remains unclear. Future works carrying out cross-comparisons with other detectors (e.g., AGILE/MCAL data with INTEGRAL/SPI-ACS, or Fermi/GBM, or Swift/BAT) will certainly constitute a more promising investigation channel to understand and clarify the origin of STEs."
Armin Vahdat Motlagh ** Investigating state transition luminosities of Galactic black hole transients in the outburst decay
We have performed a comprehensive spectral and timing analyses of Galactic black hole transients (GBHTs) during outburst decay in order to obtain the distribution of state transition luminosities. Using the archival data of the Rossi X-ray Timing Ex- plorer (RXTE), we have calculated the weighted mean for state transition luminosities of 11 BH sources in 19 different outbursts and for disk and power-law luminosities separately. We produced histograms of these luminosities in terms of Eddington luminosity fraction (ELF) and fitted them with a Gaussian. Our results show the tightest clustering in bolometric power-law luminosity with a mean logarithmic ELF of -1.58 +- 0.13 during the index transition (as the photon index starts to decrease towards the hard state). We obtained mean logarithmic ELF of -1.73 +- 0.31 during the transition to the hard state (as the photon index reaches the lowest value) and -1.35 +- 0.28 for disk black body luminosity (DBB) during transition to the hard-intermediate state (HIMS). We discussed the reasons for clustering and possible explanations for sources that show a transition luminosity significantly below or above the general trends.
Janusz Ziolkowski ** The effect of the illumination on the evolution of the binary system V821 Ara/GX 339-4
We constructed evolutionary models for V821 Ara (optical companion of GX 339-4). Our models indicate that the donor is most likely a stripped giant with mass in the range 0.22 to 1.0 M[?]. All our models predict the rate of the accretion on the compact object that is much smaller than the observed accretion rate. We discuss one of the possible solutions of this problem namely taking into account the irradiation of the donor by the X-rays from the compact object. We found that if only ~ 1 percent of the X-ray flux illuminating the donor is absorbed by the outer layers of the donor this will cause the expansion of these layers sufficient to induce the outflow at the rate comparable to the observed one. However, one must remember that he irradiation can influence the outflow (and invoke the oscillatory behavior of the mass transfer rate) only on a relatively short timescale. The outflow on the long timescale is determined by the internal structure of the donor. To reconcile this with the observed accretion rate it might be necessary to invoke the non-conservative mass transfer. We found that mass transfer during which ~ 25 to 50 percent of the mass escapes from the system carrying out the specific angular momentum comparable to that of the donor might solve the problem. We acknowledge funding from the European Union's Horizon 2020 Programme under the AHEAD project (grant agreement n. 654215).
Andrea Tramacere ** JetSeT a framework for self-consistent modeling and fitting of astrophysical relativistic jets
JetSeT is a python/C framework providing tools for: 1)reproducing radiative and accelerative process acting in relativistic jets 2)modeling and fitting multiwavelength SEDs 3)handling observed data