- ID:
- ivo://CDS.VizieR/J/ApJS/187/495
- Title:
- SNRs in M33 from optical and X-ray
- Short Name:
- J/ApJS/187/495
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- M33 contains a large number of emission nebulae identified as supernova remnants (SNRs) based on the high [SII]:H{alpha} ratios characteristic of shocked gas. Using Chandra data from the ChASeM33 survey with a 0.35-2keV sensitivity of ~2x10^34^erg/s, we have detected 82 of 137 SNR candidates, yielding confirmation of (or at least strongly support for) their SNR identifications. A spectral analysis of the seven X-ray brightest SNRs reveals that two, G98-31 and G98-35, have spectra that appear to indicate enrichment by ejecta from core-collapse supernova explosions. We have used a combination of new and archival optical and radio observations to attempt to better understand why some objects are detected as X-ray sources and others are not. We have also developed a morphological classification scheme for the optically identified SNRs and discussed the efficacy of this scheme as a predictor of X-ray detectability. Finally, we have compared the SNRs found in M33 to those that have been observed in the Galaxy and the Magellanic Clouds.
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- ID:
- ivo://CDS.VizieR/J/MNRAS/429/189
- Title:
- SNRs in six nearby galaxies
- Short Name:
- J/MNRAS/429/189
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from a study of optically emitting supernova remnants (SNRs) in six nearby galaxies (NGC 2403, 3077, 4214, 4395, 4449 and 5204) based on deep narrow-band H{alpha} and [SII] images as well as spectroscopic observations. The SNR classification was based on the detected sources that fulfil the well-established emission-line flux criterion of [SII]/H{alpha}>0.4. This study revealed ~400 photometric SNRs down to a limiting H{alpha} flux of 10^-15^erg/s/cm^2^. Spectroscopic observations confirmed the shock-excited nature of 56 out of the 96 sources with ([SII]/H{alpha})_phot_>0.3 (our limit for an SNR classification) for which we obtained spectra. 11 more sources were spectroscopically identified as SNRs although their photometric [SII]/H{alpha} ratio was below 0.3. We discuss the properties of the optically detected SNRs in our sample for different types of galaxies and hence different environments, in order to address their connection with the surrounding interstellar medium. We find that there is a difference in [NII]/H{alpha} line ratios of the SNR populations between different types of galaxies which indicates that this happens due to metallicity. We cross-correlate parameters of the optically detected SNRs ([SII]/H{alpha} ratio, luminosity) with parameters of coincident X-ray-emitting SNRs, resulted from our previous studies on the same sample of galaxies, in order to understand their evolution and investigate possible selection effects. We do not find a correlation between their H{alpha} and X-ray luminosities, which we attribute to the presence of material in a wide range of temperatures. We also find evidence for a linear relation between the number of luminous optical SNRs (10^37^erg/s) and star formation rate in our sample of galaxies.
- ID:
- ivo://CDS.VizieR/J/MNRAS/439/354
- Title:
- Sources around Tycho's Supernova 1572
- Short Name:
- J/MNRAS/439/354
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With archival and new Hubble Space Telescope observations, we have refined the space-velocity measurements of the stars in the central region of the remnant of Tycho's supernova (SN) 1572, one of the historical Galactic Type Ia supernova remnants (SNRs). We derived a proper motion for Tycho-G of (pmRAcosDE;pmDE) J2000.0 =(-2.63;,-3.98)+/-(0.06;,0.04)[formal errors] +/-(0.18;0.10)[expected errors]mas/yr. If the star were at the distance of the SNR (taken here to be 2.83kpc), its velocity would be V_b_=-51+/-1.5km/s. We also reconstruct the binary orbit that Tycho-G should have followed if it were the surviving companion of SN 1572. We redetermine the Ni abundance of this star and compare it with new abundance data from stars of the Galactic disc, finding that [Ni/Fe] is about 1.7{sigma} above the Galactic trend. From the high velocity of Tycho-G perpendicular to the Galactic plane (-90+/-3km/s<=V_b_<=-45+/-1km/s, for the allowed range of distances to the star), its metallicity and its Ni excess, we find the probability of it being a chance interloper to be P<~0.00037 at most. The projected rotational velocity of the star should be below current observational limits. The projected position of Tycho-G is, within the uncertainties, consistent with the centroid of the X-ray emission of Tycho's SNR; moreover, its brightness is generally consistent with the post-explosion evolution of the luminosity of an SN companion. Among the other 23 stars having V<22mag and located within 42-arcsec from the X-ray centroid, only 4 are at distances compatible with that of the SNR, and none of them shows any peculiarity. Therefore, if even Tycho-G is not the surviving companion of SN 1572, the absence of other viable candidates does favour the merging of two white dwarfs as the producer of the SN.
- ID:
- ivo://CDS.VizieR/J/A+A/368/267
- Title:
- Spatially resolved spectroscopy of Cas A
- Short Name:
- J/A+A/368/267
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have performed the first detailed spatially resolved spectroscopy of Cas A in the 1.6-10keV energy range, using data taken with the Medium Energy Concentrator Spectrometer (MECS) on board the BeppoSAX Observatory. The well calibrated point spread function in the central region of the MECS allowed us to perform a spatial deconvolution of the data at full energy resolution. We eventually generated a set of spectra, covering a region of ~3' radius around the centre of Cas A. The data used were obtained on Aug 1996, Sep 1996 and Nov 1997.
- ID:
- ivo://CDS.VizieR/J/A+A/595/A10
- Title:
- Spectroscopic mapping of supernova remnant N49
- Short Name:
- J/A+A/595/A10
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Physical conditions inside a supernova remnant can vary significantly between different positions. However, typical observational data of supernova remnants are integrated data or contemplate specific portions of the remnant. We study the spatial variation in the physical properties of the N49 supernova remnant based on a spectroscopic mapping of the whole nebula. Long-slit spectra were obtained with the slit (~4'x1.03") aligned along the east-west direction from 29 different positions spaced by 2" in declination. A total of 3248 1D spectra were extracted from sections of 2" of the 2D spectra. More than 60 emission lines in the range 3550{AA} to 8920{AA} were measured in these spectra. Maps of the fluxes and of intensity ratios of these emission lines were built with a spatial resolution of 2"x2".
- ID:
- ivo://CDS.VizieR/J/A+A/279/541
- Title:
- Sub-mm observations of SNR IC 443
- Short Name:
- J/A+A/279/541
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/A+A/655/A10
- Title:
- Supernova remnant G107.0+9.0 radio images
- Short Name:
- J/A+A/655/A10
- Date:
- 07 Mar 2022 07:14:09
- Publisher:
- CDS
- Description:
- The vast majority of Galactic supernova remnants (SNRs) were detected by their synchrotron radio emission. Recently, the evolved SNR G107.0+9.0 with a diameter of about 3D or 75pc up to 100pc in size was optically detected with an indication of faint associated radio emission. This SNR requires a detailed radio study. We searched for radio emission from SNR G107.0+9.0 by analysing new data from the Effelsberg 100-m and the Urumqi 25-m radio telescopes in addition to available radio surveys. Radio SNRs outside of the Galactic plane, where confusion is rare, must be very faint if they have not been identified so far. Guided by the H{alpha} emission of G107.0+9.0, we separated its radio emission from the Galactic large-scale emission. Radio emission from SNR G107.0+9.0 is detected between 22MHz and 4.8GHz with a steep non-thermal spectrum, which confirms G107.0+9.0 as an SNR. Its surface brightness is among the lowest known for Galactic SNRs. Polarised emission is clearly detected at 1.4GHz but is fainter at 4.8GHz. We interpret the polarised emission as being caused by a Faraday screen associated with G107.0+9.0 and its surroundings. Its ordered magnetic field along the line of sight is below 1-microG. At 4.8GHz, we identified a depolarised filament along the western periphery of G107.0+9.0 with a magnetic field strength along the line of sight B_parallel_~15-microG, which requires magnetic field compression. G107.0+9.0 adds to the currently small number of known, evolved, large-diameter, low-surface-brightness Galactic SNRs. We have shown that such objects can be successfully extracted from radio-continuum surveys despite the dominating large-scale diffuse Galactic emission.
- ID:
- ivo://CDS.VizieR/J/AZh/71/110
- Title:
- Supernova Remnants at Meter Wavelengths
- Short Name:
- J/AZh/71/110
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The total flux densities of more than one hundred galactic supernova remnants (SNR) at 111, 102, and 83MHz, measured at Pushchino using the E-W WBCR-1000 and LSA radio telescopes, to an accuracy of 2Jy or better; the spectral indices, with their errors, obtained from the compiled spectra; and optical depths at 100MHz in the direction of the supernova remnants are reported. The latter values are obtained from a low frequency cutoff caused by interstellar gas absorption, which was detected at meter and decimeter wavelengths in the direction of 38% of the supernova remnants.
- ID:
- ivo://CDS.VizieR/J/ApJS/120/247
- Title:
- Supernova remnants in M33
- Short Name:
- J/ApJS/120/247
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using radio data to identify and optical data to confirm, we have established the largest and most complete sample of extragalactic radio-bright supernova remnants (SNRs) in the nearby spiral galaxy M33. We have identified 53 radio SNRs, doubling the size of the earlier survey by Duric et al. (1993A&AS...99..217D).
- ID:
- ivo://CDS.VizieR/J/MNRAS/472/308
- Title:
- Supernova remnants in M33: X-ray properties
- Short Name:
- J/MNRAS/472/308
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a study of the X-ray properties of the supernova remnant (SNR) population in M33 with XMM-Newton, comprising deep observations of eight fields in M33 covering all of the area within the D_25_ contours, and with a typical luminosity of 7.1x10^34^erg/s (0.2-2.0keV). Here, we report our work to characterize the X-ray properties of the previously identified SNRs in M33, as well as our search for new X-ray detected SNRs. With our deep observations and large field of view we have detected 105 SNRs at the 3{sigma} level, of which 54 SNRs are newly detected in X-rays, and three are newly discovered SNRs. Combining XMM-Newton data with deep Chandra survey data allows detailed spectral fitting of 15 SNRs, for which we have measured temperatures, ionization time-scales and individual abundances. This large sample of SNRs allows us to construct an X-ray luminosity function, and compare its shape to luminosity functions from host galaxies of differing metallicities and star formation rates to look for environmental effects on SNR properties. We conclude that while metallicity may play a role in SNR population characteristics, differing star formation histories on short time-scales, and small-scale environmental effects appear to cause more significant differences between X-ray luminosity distributions. In addition, we analyse the X-ray detectability of SNRs, and find that in M33 SNRs with higher [SII]/H{alpha} ratios, as well as those with smaller galactocentric distances, are more detectable in X-rays.
