- ID:
- ivo://CDS.VizieR/J/A+A/602/A31
- Title:
- G29.37+0.1 610MHz image
- Short Name:
- J/A+A/602/A31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report on the first detailed multiwavelength study of the radio source G29.37+0.1, which is an as-yet-unclassified object linked to the very-high-energy gamma-emitting source HESS J1844-030. The origin of the multiwavelength emission toward G29.37+0.1 has not been clarified so far, leaving open the question about the physical relationship between these sources. Using observations carried out with the Giant Metrewave Radio Telescope (GMRT), we performed high-quality full-synthesis imaging at 610MHz of the field containing G29.37+0.1. The obtained data, combined with observations at 1400MHz from the MAGPIS were used to investigate in detail the properties of its radio emission. Additionally, we reprocessed archival data obtained with the XMM-Newton and Chandra observatories in order to get a multiwavelength view of this unusual source. The radio source G29.37+0.1 mainly consists of a bright twisted structure, named the S-shaped feature. The high sensitivity of the new GMRT observations allowed the identification of potential lobes, jets and a nuclear central region in the S-shaped morphology of G29.37+0.1. We also highlight the detection of diffuse and low surface brightness emission enveloping the brightest emitting regions. The brightest emission in G29.37+0.1 has a radio synchrotron spectral index alpha=0.59+/-0.09. Variations in the spectral behaviour are observed across the whole radio source with the flattest spectral features in the central nuclear and jets components (alpha~0.3). These results lead us to conclude that the brightest radio emission from G29.37+0.1 likely represents a newly recognized radio galaxy. The identification of optical and infrared counterparts to the emission arising from the core of G29.37+0.1 strengthens our interpretation of an extragalactic origin of the radio emission. We performed several tests to explain the physical mechanism responsible for the observed X-ray emission, which appears overlapping the northeastern part of the radio emission. Our spectral analysis demonstrated that a non-thermal origin for the X-ray emission compatible with a pulsar wind nebula is quite possible. The analysis of the spatial distribution of the CO gas revealed the presence of a complex of molecular clouds located in projection adjacent to the radio halo emission and probably interacting with it. We propose that the faint halo represents a composite supernova remnant with a pulsar powered component given by the diffuse X-ray emission superimposed along the line of sight to the radio galaxy. Further broadband observations of HESS J1844-030 are needed to disentangle its origin, although its shape and position suggest an extragalactic origin connected to G29.37+0.1.
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Search Results
- ID:
- ivo://CDS.VizieR/J/A+A/597/A80
- Title:
- GMVA 86GHz images of OJ 287
- Short Name:
- J/A+A/597/A80
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The gamma-ray BL Lac object OJ 287 is known to exhibit inner-parsec "jet-wobbling", high degrees of variability at all wavelengths and quasi-stationary features, including an apparent (~100{deg}) position-angle change in projection on the sky plane. Sub-50 micro-arcsecond resolution 86GHz observations with the global mm-VLBI array (GMVA) supplement ongoing multifrequency VLBI blazar monitoring at lower frequencies. Using these maps, together with cm/mm total intensity and gamma-ray observations from Fermi/LAT from 2008-2014, we aim to determine the location of gamma-ray emission and to explain the inner-mas structural changes. Observations with the GMVA offset approximately double the angular resolution compared with 43GHz VLBA observations and enable us to observe above the synchrotron self-absorption peak frequency. Fermi-LAT gamma-ray data were reduced and analysed. The jet was spectrally decomposed at multiple locations along the jet. From this, we could derive estimates of the magnetic field using equipartition and synchrotron self-absorption arguments. How the field decreases down the jet provided an estimate of the distance to the jet apex and an estimate of the magnetic field strength at the jet apex and in the broad line region. Combined with accurate kinematics, we attempt to locate the site of gamma-ray activity, radio flares, and spectral changes.
- ID:
- ivo://CDS.VizieR/IX/36
- Title:
- GRANAT/PHEBUS catalog of cosmic gamma-ray bursts
- Short Name:
- IX/36
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Phebus instrument, a part of scientific equipment on board the Granat astrophysical Observatory, has the purpose to study cosmic gamma-ray bursts and solar flares in the range from 100keV to 100MeV. This is the final catalog of cosmic gamma-ray bursts (GRBs) observed in the PHEBUS experiment Granat orbiting astrophysical observatory. This catalogue contains information on 66 events recorded from December 1989 to May 199, 52 events recorded from June 1991 to December 199, 60 events recorded from January 1993 until September 1994, and 32 events recorded from October 1994 until December 1996. We provide the GRB light curves in the range 100keV - 1.6MeV, energy spectra and data on the total energy fluxes and energy fluxes at GRB luminosity peaks at energies above 100keV.
- ID:
- ivo://CDS.VizieR/J/A+AS/129/1
- Title:
- GRANAT/WATCH catalogue of gamma-ray bursts
- Short Name:
- J/A+AS/129/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the catalogue of gamma-ray bursts (GRB) observed with the WATCH all-sky monitor on board the GRANAT satellite during the period December 1989 to September 1994. The cosmic origin of 95 bursts comprising the catalogue is confirmed either by their localisation with WATCH or by their detection with other GRB experiments. For each burst its time history and information on its intensity in the two energy ranges 8-20keV and 20-60keV are presented. Most events show hardening of the energy spectrum near the burst peak. In part of the bursts an X-ray precursor or a tail is seen at 8-20keV. We have determined the celestial positions of the sources of 47 bursts. Their localisation regions (at 3-sigma confidence level) are equivalent in area to circles with radii ranging from 0.2 to 1.6deg. The burst sources appear isotropically distributed on the sky on large angular scales.
- ID:
- ivo://CDS.VizieR/J/ApJ/715/1438
- Title:
- Gravitational-wave bursts with GRBs
- Short Name:
- J/ApJ/715/1438
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of a search for gravitational-wave bursts (GWBs) associated with 137 gamma-ray bursts (GRBs) that were detected by satellite-based gamma-ray experiments during the fifth LIGO science run and first Virgo science run. The data used in this analysis were collected from 2005 November 4 to 2007 October 1, and most of the GRB triggers were from the Swift satellite. The search uses a coherent network analysis method that takes into account the different locations and orientations of the interferometers at the three LIGO-Virgo sites. We find no evidence for GWB signals associated with this sample of GRBs. Using simulated short-duration (<1s) waveforms, we set upper limits on the amplitude of gravitational waves associated with each GRB. We also place lower bounds on the distance to each GRB under the assumption of a fixed energy emission in gravitational waves, with a median limit of D~12Mpc(E^iso^_GW_/0.01M_{sun}_c^2^)^1/2^ for emission at frequencies around 150Hz, where the LIGO-Virgo detector network has best sensitivity.
- ID:
- ivo://CDS.VizieR/J/ApJ/814/1
- Title:
- GRB 120326A, 100418A & 100901A multi-wavelength obs.
- Short Name:
- J/ApJ/814/1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present multi-wavelength observations and modeling of gamma-ray bursts (GRBs) that exhibit a simultaneous re-brightening in their X-ray and optical light curves, and are also detected at radio wavelengths. We show that the re-brightening episodes can be modeled by injection of energy into the blastwave and that in all cases the energy injection rate falls within the theoretical bounds expected for a distribution of energy with ejecta Lorentz factor. Our measured values of the circumburst density, jet opening angle, and beaming-corrected kinetic energy are consistent with the distribution of these parameters for long-duration GRBs at both z~1 and z>~6, suggesting that the jet launching mechanism and environment of these events are similar to that of GRBs that do not have bumps in their light curves. However, events exhibiting re-brightening episodes have lower radiative efficiencies than average, suggesting that a majority of the kinetic energy of the outflow is carried by slow-moving ejecta, which is further supported by steep measured distributions of the ejecta energy as a function of Lorentz factor. We do not find evidence for reverse shocks over the energy injection period, implying that the onset of energy injection is a gentle process. We further show that GRBs exhibiting simultaneous X-ray and optical re-brightenings are likely the tail of a distribution of events with varying rates of energy injection, forming the most extreme events in their class. Future X-ray observations of GRB afterglows with Swift and its successors will thus likely discover several more such events, while radio follow-up and multi-wavelength modeling of similar events will unveil the role of energy injection in GRB afterglows.
- ID:
- ivo://CDS.VizieR/J/A+A/607/A29
- Title:
- GRB 120327A afterglow colour variations
- Short Name:
- J/A+A/607/A29
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a comprehensive temporal and spectral analysis of the long Swift GRB120327A afterglow data to investigate the possible causes of the observed early time colour variations. We collected data from various instruments/telescopes in X-ray, ultra-violet, optical and near-infrared bands and determined the shapes of the afterglow early-time light curves. We studied the overall temporal behaviour and the spectral energy distributions from early to late times. The ultra-violet, optical, and near-infrared light curves can be modelled with a single power-law component between 200 and 2x10^4^s after the burst event. The X-ray light curve shows a canonical steep-shallow-steep behaviour, typical of long gamma-ray bursts. At early times a colour variation is observed in the ultra-violet/optical bands, while at very late times a hint of a re-brightening is visible. The observed early time colour change can be explained as a variation in the intrinsic optical spectral index, rather than an evolution of the optical extinction.
- ID:
- ivo://CDS.VizieR/J/A+A/557/A18
- Title:
- GRB 120815A afterglow spectra
- Short Name:
- J/A+A/557/A18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the discovery of molecular hydrogen (H_2_), including the presence of vibrationally-excited H_2^*^_ in the optical spectrum of the afterglow of GRB 120815A at z=2.36 obtained with X-shooter at the VLT. Simultaneous photometric broad-band data from GROND and X-ray observations by Swift/XRT place further constraints on the amount and nature of dust along the sightline. The galactic environment of GRB 120815A is characterized by a strong DLA with would allow statistical studies, and, coupled with host follow-up and sub-mm spectroscopy, provide unprecedented insights into the process and conditions of star-formation at high redshift.
- ID:
- ivo://CDS.VizieR/J/A+A/564/A38
- Title:
- GRB 120327A afterglow VLT/X-shooter spectroscopy
- Short Name:
- J/A+A/564/A38
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a study of the environment of the Swift long gamma-ray burst GRB 120327A at z~2.8 through optical spectroscopy of its afterglow. We analyzed medium-resolution, multi-epoch spectroscopic observations (R~7000-12000, corresponding to ~15-23km/s, S/N=15-30 and wavelength range 3000-25000{AA}) of the optical afterglow of GRB 120327A, taken with X-shooter at the VLT 2.13 and 27.65hr after the GRB trigger.
- ID:
- ivo://CDS.VizieR/J/MNRAS/421/1874
- Title:
- GRB 100901A and GRB 100906A light curves
- Short Name:
- J/MNRAS/421/1874
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the results of the prompt, early and afterglow optical observations of five {gamma}-ray bursts (GRBs): GRB 100901A, GRB 100902A, GRB 100905A, GRB 100906A and GRB 101020A. These observations were made with the Mobile Astronomical System of TElescope-Robots in Russia (MASTER-II Net), the 1.5-m telescope of the Sierra Nevada Observatory and the 2.56-m Nordic Optical Telescope.
