scholarly journals Radio Supernovae

1996 ◽  
Vol 145 ◽  
pp. 283-297 ◽  
Author(s):  
Kurt W. Weiler ◽  
Schuyler D. Van Dyk ◽  
Richard A. Sramek ◽  
Nino Panagia
Keyword(s):  
Radio Emission ◽  
Supernova Remnant ◽  
Optical Emission ◽  
Late Time ◽  
Powerful Radio ◽  
Distance Measurements ◽  
X Ray ◽  
Circumstellar Material ◽  
Cas A ◽  
Progenitor Stars

Radio observations have shown that some supernovae are powerful radio emitters which increase rapidly in brightness to radio luminosities which are hundreds to thousands of times greater than even the brightest known supernova remnant, Cas A. They then fade over a period of weeks, months, or years. This radio emission has been found to provide important information about the nature of the progenitor stars, their mass loss rates, and the circumstellar material surrounding them. RSN observations may also offer the possibility of extragalactic distance measurements and the presence of radio emission appears to be indicator of strong x-ray emission and late time optical emission.

scholarly journals A Galactic dust devil: far-infrared observations of the Tornado supernova remnant candidate

2020 ◽  
Vol 499 (4) ◽  
pp. 5665-5678
Author(s):  
H Chawner ◽  
A D P Howard ◽  
H L Gomez ◽  
M Matsuura ◽  
F Priestley ◽  
...  
Keyword(s):  
Radio Emission ◽  
Supernova Remnant ◽  
Far Infrared ◽  
Large Mass ◽  
Dust Devils ◽  
Infrared Observations ◽  
X Ray ◽  
Ss 433 ◽  
Multiple Regions ◽  
Tail Structure

ABSTRACT We present complicated dust structures within multiple regions of the candidate supernova remnant (SNR) the ‘Tornado’ (G357.7–0.1) using observations with Spitzer and Herschel. We use point process mapping, ppmap, to investigate the distribution of dust in the Tornado at a resolution of 8 arcsec, compared to the native telescope beams of 5–36 arcsec. We find complex dust structures at multiple temperatures within both the head and the tail of the Tornado, ranging from 15 to 60 K. Cool dust in the head forms a shell, with some overlap with the radio emission, which envelopes warm dust at the X-ray peak. Akin to the terrestrial sandy whirlwinds known as ‘dust devils’, we find a large mass of dust contained within the Tornado. We derive a total dust mass for the Tornado head of 16.7 $\rm M_{\odot }$, assuming a dust absorption coefficient of κ300 = 0.56 $\rm m^2\, kg^{-1}$, which can be explained by interstellar material swept up by a SNR expanding in a dense region. The X-ray, infrared, and radio emission from the Tornado head indicate that this is a SNR. The origin of the tail is more unclear, although we propose that there is an X-ray binary embedded in the SNR, the outflow from which drives into the SNR shell. This interaction forms the helical tail structure in a similar manner to that of the SNR W50 and microquasar SS 433.

scholarly journals Discovery and follow-up of ASASSN-19dj: an X-ray and UV luminous TDE in an extreme post-starburst galaxy

2020 ◽  
Vol 500 (2) ◽  
pp. 1673-1696 ◽  
Author(s):  
Jason T Hinkle ◽  
T W-S Holoien ◽  
K Auchettl ◽  
B J Shappee ◽  
J M M Neustadt ◽  
...  
Keyword(s):  
Optical Emission ◽  
Starburst Galaxy ◽  
Late Time ◽  
X Rays ◽  
Tidal Disruption ◽  
X Ray ◽  
Bolometric Luminosity ◽  
Order Of Magnitude ◽  
High Cadence

ABSTRACT We present observations of ASASSN-19dj, a nearby tidal disruption event (TDE) discovered in the post-starburst galaxy KUG 0810+227 by the All-Sky Automated Survey for Supernovae (ASAS-SN) at a distance of d ≃ 98 Mpc. We observed ASASSN-19dj from −21 to 392 d relative to peak ultraviolet (UV)/optical emission using high-cadence, multiwavelength spectroscopy and photometry. From the ASAS-SN g-band data, we determine that the TDE began to brighten on 2019 February 6.8 and for the first 16 d the rise was consistent with a flux ∝t2 power law. ASASSN-19dj peaked in the UV/optical on 2019 March 6.5 (MJD = 58548.5) at a bolometric luminosity of L = (6.2 ± 0.2) × 1044 erg s−1. Initially remaining roughly constant in X-rays and slowly fading in the UV/optical, the X-ray flux increased by over an order of magnitude ∼225 d after peak, resulting from the expansion of the X-ray emitting region. The late-time X-ray emission is well fitted by a blackbody with an effective radius of ∼1 × 1012 cm and a temperature of ∼6 × 105 K. The X-ray hardness ratio becomes softer after brightening and then returns to a harder state as the X-rays fade. Analysis of Catalina Real-Time Transient Survey images reveals a nuclear outburst roughly 14.5 yr earlier with a smooth decline and a luminosity of LV ≥ 1.4 × 1043 erg s−1, although the nature of the flare is unknown. ASASSN-19dj occurred in the most extreme post-starburst galaxy yet to host a TDE, with Lick HδA = 7.67 ± 0.17 Å.

scholarly journals Models for the Emission Line Spectra of Oxygen-rich Supernova Remnants

1987 ◽  
Vol 40 (6) ◽  
pp. 789 ◽  
Author(s):  
Michael A Dopita
Keyword(s):  
Supernova Remnants ◽  
Optical Emission ◽  
Theoretical Modelling ◽  
Optical Data ◽  
X Ray ◽  
Elemental Abundances ◽  
Current State ◽  
Enormous Amount ◽  
Degree Of Confidence ◽  
Cas A

The mechanism of excitation of the oxygen-rich class of young supernova remnants (SNRs), typified by the fast-moving knots of Cas A, is not currently understood. In this paper we review the available optical data and the current state of attempts at theoretical modelling. A new model is proposed which dramatically improves the fit of the theory with the observations for this class of SNRs. The model is of an X-ray driven R-type ionisation front precursor of a very fast shock. The peculiarities of the thermal balance in oxygen allow an enormous amount of superheating in the gas, which is first exposed to the X-ray ionising field, and the optical emission occurs in this superheated gas. The fit with observation is sufficiently good to give some degree of confidence that the mode of excitation of the plasma has at last been identified, and elemental abundances in four young oxygen-rich SNRs are derived.

On Interpretations of Observed Radio Properties of Cas A

1979 ◽  
Vol 3 (5) ◽  
pp. 347-348
Author(s):  
I. Lerche† ◽  
J. L. Caswell
Keyword(s):  
Radio Emission ◽  
Surface Brightness ◽  
Supernova Remnant ◽  
Detailed Comparison ◽  
Cas A

Cas A has a radio surface brightness much higher (by a factor of about 100) than that of any other galactic supernova remnant (SNR) and is probably the youngest (≤ 300 yr). It therefore provides unique information on young remnants, but this very uniqueness makes it hazardous to treat Cas A as a typical remnant. However, because it (i) shows a clearly defined shell of radio emission of much the same type as older remnants, and (ii) lies approximately on the extrapolation of the Σ.-D (surface brightness-diameter) relationship derived for older remnants (Clark and Caswell 1976); Caswell and Lerche 1979a), detailed comparison with older remnants seems appropriate.

scholarly journals Search for Nonthermal X-Rays from Supernova Remnant Shells

1998 ◽  
Vol 188 ◽  
pp. 117-120
Author(s):  
R. Petre ◽  
J. Keohane ◽  
U. Hwang ◽  
G. Allen ◽  
E. Gotthelf
Keyword(s):  
Radio Emission ◽  
Supernova Remnants ◽  
Supernova Remnant ◽  
Cosmic Ray ◽  
High Energy ◽  
X Rays ◽  
X Ray ◽  
Nonthermal Radio ◽  
Cosmic Ray Acceleration ◽  
Nonthermal Radio Emission

The suggestion that the shocks of supernova remnants (SNR's) are cosmic ray acceleration sites dates back more than 40 years. While observations of nonthermal radio emission from SNR shells indicate the ubiquity of GeV cosmic ray production, there is still theoretical debate about whether SNR shocks accelerate particles up to the well-known “knee” in the primary cosmic ray spectrum at ~3,000 TeV. Recent X-ray observations of SN1006 and other SNR's may have provided the missing observational link between SNR shocks and high energy cosmic ray acceleration. We discuss these observations and their interpretation, and summarize our ongoing efforts to find evidence from X-ray observations of cosmic ray acceleration in the shells of other SNR's.

scholarly journals Stellar X-Ray Sources

1974 ◽  
Vol 60 ◽  
pp. 383-399
Author(s):  
Harvey D. Tananbaum
Keyword(s):  
Black Hole ◽  
Radio Emission ◽  
Optical Emission ◽  
Close Correlation ◽  
X Ray ◽  
Radio Outburst ◽  
The Relationship ◽  
Optical Behavior

Data are presented for Cygnus X-1, Cygnus X-3, and Scorpius X-1 from radio to X-ray wavelengths. The evidence for Cygnus X-1's being a black hole is now quite convincing. New data for Cygnus X-3 show the presence of X-ray activity at the time of the giant radio outburst. The data for Scorpius X-1 show a close correlation between the X-ray and optical behavior, but coverage was not sufficiently complete to fully assess the relationship (if any) between the X-ray and optical emission and the radio emission.

scholarly journals X-ray Observations of SNR E0102.2-72.2 in the SMC

1988 ◽  
Vol 101 ◽  
pp. 125-128
Author(s):  
John P. Hughes
Keyword(s):  
High Resolution ◽  
Emission Line ◽  
Spectral Data ◽  
Proportional Counter ◽  
High Velocity ◽  
Supernova Remnant ◽  
Optical Emission ◽  
Small Magellanic Cloud ◽  
X Ray ◽  
Best Fit

AbstractThe supernova remnant (SNR) E0102.2-72.2 is the brightest in the Small Magellanic Cloud (SMC) at X-ray wavelengths. This object, which is remarkable because of its high velocity (∼4000 km s−1) oxygen-rich optical emission, appears to be similarly remarkable at X-ray wavelengths. The high resolution imager (HRI) data can be quite well described by a thick ring with a radius of ∼19" (6 pc at a distance of 63 kpc). The imaging proportional counter (IPC) X-ray spectral data can be best fit by a single emission line of energy ∼0.9 keV. It seems likely that this is the emission from a plasma of almost pure neon.

scholarly journals LATE-TIME RADIO EMISSION FROM X-RAY-SELECTED TIDAL DISRUPTION EVENTS

2013 ◽  
Vol 763 (2) ◽  
pp. 84 ◽  
Author(s):  
Geoffrey C. Bower ◽  
Brian D. Metzger ◽  
S. Bradley Cenko ◽  
Jeffrey M. Silverman ◽  
Joshua S. Bloom
Keyword(s):  
Radio Emission ◽  
Late Time ◽  
Tidal Disruption ◽  
X Ray

scholarly journals The Secular Behavior of X-Ray and Radio Emission from Supernova Remnants

1971 ◽  
Vol 46 ◽  
pp. 268-272
Author(s):  
Wallace H. Tucker
Keyword(s):  
Radio Emission ◽  
Supernova Remnants ◽  
Crab Nebula ◽  
X Ray ◽  
Cas A ◽  
The Crab Nebula ◽  
Continuous Injection

Continuous injection models for the secular behavior of the radio and X-ray emission from supernova remnants are examined and compared with the observations. Among other things, it is concluded that (1) continuous injection probably occurs for at least 10 yr in every case and about 1000 yr in most supernova remnants, in which case the supernova remnants 3C392, W28, Pup A and IC443 should produce 1–10 keV X-ray fluxes ≈ 10-10 ergs/cm2-sec, and (2) the X-ray sources in the Crab Nebula, Cas A and Tycho can be explained in terms of a model wherein continuous injection occurs for 300 yr for the Crab Nebula, much less than 250 yr for Cas A and much longer than 400 yr for Tycho. Finally, it is shown that if Tycho and Cas A contain an X-ray star such as NP 0532, it is quite possible that the X-ray emission from those sources is predominantly due to the X-ray star.

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