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An exploration of X-ray Supernova remnants in the Milky Way and nearby galaxies
ABSTRACT We probe the environmental properties of X-ray supernova remnants (SNRs) at various points along their evolutionary journey, especially the S-T phase, and their conformance with theoretically derived models of SNR evolution. The remnant size is used as a proxy for the age of the remnant. Our data set includes 34 Milky Way, 59 Large Magellanic Cloud (LMC), and 5 Small Magellanic Cloud (SMC) SNRs. We select remnants that have been definitively typed as either core-collapse (CC) or Type Ia supernovae, with well-defined size estimates, and a thermal X-ray flux measured over the entire remnant. A catalog of SNR size and X-ray luminosity is presented and plotted, with ambient density and age estimates from the literature. Model remnants with a given density, in the Sedov-Taylor (S-T) phase, are overplotted on the diameter-versus-luminosity plot, allowing the evolutionary state and physical properties of SNRs to be compared to each other, and to theoretical models. We find that small, young remnants are predominantly Type Ia remnants or high luminosity CCs, suggesting that many CC SNRs are not detected until after they have emerged from the progenitor’s wind-blown bubble. An examination of the distribution of SNR diameters in the Milky Way and LMC reveals more »
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Award ID(s):
Publication Date:
NSF-PAR ID:
10347652
Journal Name:
Monthly Notices of the Royal Astronomical Society
Volume:
514
Issue:
1
Page Range or eLocation-ID:
728 to 743
ISSN:
0035-8711
5. ABSTRACT Within lambda cold dark matter ($\Lambda$CDM), dwarf galaxies like the Large Magellanic Cloud (LMC) are expected to host numerous dark matter subhaloes, several of which should host faint dwarf companions. Recent Gaia proper motions confirm new members of the LMC system in addition to the previously known SMC, including two classical dwarf galaxies ($M_\ast$$\gt 10^5 M_{\odot }; Carina and Fornax) as well as several ultrafaint dwarfs (Car2, Car3, Hor1, and Hyd1). We use the Feedback In Realistic Environments (FIRE) simulations to study the dark and luminous (down to ultrafaint masses, M_\ast$$\sim$6$\times 10^ {3}$ M$_{\odot }$) substructure population of isolated LMC-mass hosts ($M_{\text{200m}}$ = 1–3$\times 10^ {11}$ M$_{\odot }$) and place the Gaia  + DES results in a cosmological context. By comparing number counts of subhaloes in simulations with and without baryons, we find that, within 0.2 $r_{\text{200m}}$, LMC-mass hosts deplete $\sim$30 per cent of their substructure, significantly lower than the $\sim$70 per cent of substructure depleted by Milky Way (MW) mass hosts. For our highest resolution runs ($m_\text{bary}$  = 880 M$_{\odot }$), $\sim 5\!-\!10$ subhaloes form galaxies with $M_\ast$$\ge 10^{4}$ M$_{\odot }$ , in agreement with the seven observationally inferred pre-infall LMC companions. However, we find steeper simulated luminosity functions than observed, hinting at observation incompleteness at the faintmore »