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Related papers: Non-Thermal Continuum toward SGRB2(N-LMH)

200 papers

Recent advances in fitting prompt emission spectra in gamma-ray bursts (GRBs) are boosting our understanding of the still elusive origin of this radiation. These progresses have been possible thanks to a more detailed analysis of the…

High Energy Astrophysical Phenomena · Physics 2018-02-07 Lara Nava , Gor Oganesyan , Maria E. Ravasio , Lorenzo Amati , Giancarlo Ghirlanda , Paul O'Brien , Julian P. Osborne , Richard Willingale

We present Giant Metrewave Radio Telescope (GMRT) 323 MHz radio continuum observations toward 13 radio-loud quasars at $z>5$, sampling the low-frequency synchrotron emission from these objects. Among the 12 targets successfully observed, we…

Astrophysics of Galaxies · Physics 2020-09-16 Yali Shao , Jeff Wagg , Ran Wang , Chris L. Carilli , Dominik A. Riechers , Huib T. Intema , Axel Weiss , Karl M. Menten

We report the detection of Voigt spectral line profiles of radio recombination lines (RRLs) toward Sagittarius B2(N) with the 100-m Green Bank Telescope (GBT). At radio wavelengths, astronomical spectra are highly populated with RRLs, which…

X-ray spectra of nonmagnetic cataclysmic variables (nmCVs) in the ~ 0.3$-$15 keV energy band have been described either by one or several optically thin thermal plasma components, or by cooling flow models. We tested if the spectral…

High Energy Astrophysical Phenomena · Physics 2020-08-11 T. Maiolino , L. Titarchuk , F. D'Amico , Z. Q. Cheng , W. Wang , M. Orlandini , Filippo Frontera

I explore the observational appearance of the photosphere of an ultrarelativistic flow with internal dissipation of energy (``dissipative'' GRB models). As a case study, I use the magnetic reconnection model (AC model) that makes robust…

Astrophysics · Physics 2008-11-26 Dimitrios Giannios

Plasma scattering measurement is effective technique to observe low frequency density fluctuations excited in plasma. The spatial and wave number resolutions and the S/N ratio of measurement depend on the wavelength range, the size and the…

We present high resolution X-ray spectroscopy of two recent GRB afterglows observed with the Low Energy Transmission Gratings on Chandra. The afterglows to GRBs 030328 and 041006 are detected beginning 15.33 and 16.8 hours after each burst,…

Using the data acquired in the Time To Spill (TTS) mode for long gamma-ray bursts (GRBs) collected by the Burst and Transient Source Experiment on board the Compton Gamma Ray Observatory (BATSE/CGRO), we have carefully measured spectral…

Astrophysics · Physics 2009-11-10 L. Chen , Y. Q. Lou , M. Wu , J. L. Qu , S. M. Jia , X. J. Yang

We have used the Odin submillimetre-wave satellite telescope to observe the ground state transitions of ortho-ammonia and ortho-water, including their 15N, 18O, and 17O isotopologues, towards Sgr B2. The extensive simultaneous velocity…

In this paper, we present the results of an observational search for gas phase urea [(NH$_2$)$_2$CO] observed towards the Sgr B2(N-LMH) region. We show data covering urea transitions from $\sim$100 GHz to 250 GHz from five different…

We present new Very Large Array observations at five frequencies, from 1.4 to 22GHz, of the extremely low-metallicity blue compact dwarf SBS0335-052. The radio spectrum shows considerable absorption at 1.49GHz, and a composite…

Astrophysics · Physics 2009-11-10 Leslie K. Hunt , Kristy K. Dyer , Trinh X. Thuan , James S. Ulvestad

We present high sensitivity H91$\alpha$ and 3.5 cm radio continuum observations toward the planetary nebula NGC 3242. The electron temperature determined assuming local thermodynamic equilibrium is consistent within $\sim$10% with that…

Astrophysics of Galaxies · Physics 2009-11-04 Luis F. Rodriguez , Yolanda Gomez , J. Alberto Lopez , Ma. Teresa Garcia-Diaz , David M. Clark

Gamma-Ray Transient Monitor (GTM) is an all-sky monitor onboard the Distant Retrograde Orbit-A (DRO-A) satellite, with the scientific objective of detecting gamma-ray bursts in the energy range of 20 keV to 1 MeV. GTM is equipped with five…

Using the Mopra telescope, we have undertaken a 3-mm spectral-line imaging survey of a 5 x 5 arcmin^2 area around Sgr B2. We covered almost the complete spectral the range from 81.7 to 113.5 GHz, with 2.2 MHz wide spectral channels or ~ 6…

We present 33\,GHz photometry of 103 galaxy nuclei and extranuclear star-forming complexes taken with the Green Bank Telescope (GBT) as part of the Star Formation in Radio Survey (SFRS). Among the sources without evidence for an AGN, and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 E. J. Murphy , J. Bremseth , B. S. Mason , J. J. Condon , E. Schinnerer , G. Aniano , L. Armus , G. Helou , J. L. Turner , T. H. Jarrett

We present ISO observations of the S(0), S(1), S(2), and S(3) rotational lines of molecular hydrogen from two molecular clouds near the Galactic Center (GC). We have also measured continuum dust emission at infrared wavelengths with ISO and…

The existence of excess absorption in the X-ray spectra of GRBs is well known, but the primary location of the absorbing material is still uncertain. To gain more knowledge about this, we have performed a time-resolved analysis of the X-ray…

High Energy Astrophysical Phenomena · Physics 2023-02-22 Vlasta Valan , Josefin Larsson , Björn Ahlgren

We present the results of a spectroscopic search for narrow emission and absorption features in the X-ray spectra of long gamma-ray burst (GRB) afterglows. Using XMM-Newton data, both EPIC and RGS spectra, of six bright (fluence >10^{-7}…

High Energy Astrophysical Phenomena · Physics 2016-08-03 S. Campana , V. Braito , P. D'Avanzo , G. Ghirlanda , A. Melandri , A. Pescalli , O. S. Salafia , R. Salvaterra , G. Tagliaferri , S. D. Vergani

The discovery of Gamma-Ray Burst (GRB) afterglows revealed a new class of variable sources at optical and radio wavelengths. At present, the environment and precise redshift of the detected afterglows are still unknown. We show that if a…

Astrophysics · Physics 2009-10-30 Rosalba Perna , Abraham Loeb

From 1979--1996 the Green Bank Interferometer was used by the Naval Research Laboratory to monitor the flux density from 146 compact radio sources at frequencies near 2 and 8 GHz. We filter the ``light curves'' to separate intrinsic…

Astrophysics · Physics 2009-11-11 B. Rickett , T. J. W. Lazio , F. D. Ghigo