Interstellar-Medium Mapping in M82 Through Light Echoes Around Supernova 2014J
Yi Yang, Lifan Wang, Dietrich Baade, Peter J. Brown, Misty Cracraft, Peter A. Hoflich, Justyn Maund, Ferdinando Patat, William B. Sparks, Jason Spyromilio, Helo… 展开作者
Yi Yang, Lifan Wang, Dietrich Baade, Peter J. Brown, Misty Cracraft, Peter A. Hoflich, Justyn Maund, Ferdinando Patat, William B. Sparks, Jason Spyromilio, Heloise F. Stevance, Xiaofeng Wang, J. Craig Wheeler
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45 pages, 16 figures, accepted for publication in The Astrophysical Journal
We present multiple-epoch measurements of the size and surface brightness of the light echoes from supernova (SN) 2014J in the nearby starburst galaxy M82. Hubble Space Telescope (HST) ACS/WFC images were taken ~277 and ~416 days after B-band maximum in the filters F475W, F606W, and F775W. Observations with HST WFC3/UVIS images at epochs ~216 and ~365 days (Crotts 2015) are included for a more complete analysis. The images reveal the temporal evolution of at least two major light-echo components. The first one exhibits a filled ring structure with position-angle-dependent intensity. This radially extended, diffuse echo indicates the presence of an inhomogeneous interstellar dust cloud ranging from ~100 pc to ~500 pc in the foreground of the SN. The second echo component appears as an unresolved luminous quarter-circle arc centered on the SN. The wavelength dependence of scattering measured in different dust components suggests that the dust producing the luminous arc favors smaller grain sizes, while that causing the diffuse light echo may have sizes similar to those of the Milky Way dust. Smaller grains can produce an optical depth consistent with that along the supernova-Earth line of sight measured by previous studies around maximum light. Therefore, it is possible that the dust slab, from which the luminous arc arises, is also responsible for most of the extinction towards SN 2014J. The optical depths determined from the Milky Way-like dust in the scattering matters are lower than that produced by the dust slab.
We present the analysis of four hours of spectroscopic observations of NGC 6946 with the SITELLE Imaging Fourier Transform Spectrometer on the Canada-France-Hawaii Telescope, acquired to search for supernova light echoes from its ten modern supernovae. We develop a novel spectroscopic search method: identifying negatively sloped continua in the narrow-band SN3 filter as candidate highly-broadened P-Cygni profiles in the H$α$ line, which would be characteristic of the spectra of supernovae ejecta. We test our methodology by looking for light echoes from any of the ten supernovae observed in NGC…
Type Ia SN 2014J exploded in the nearby starburst galaxy M82 = NGC 3032, and was discovered at Earth about seven days later on 2014 January 21, reaching V maximum light around 2014 February 5. SN 2014J is the closest SN Ia in at least four decades and probably many more. Recent HST/WFC3 imaging (2014 September 5 and 2015 February 2) of M82 around SN 2014J reveals a light echo at radii of about 0.6 arcsec from the SN (corresponding to about 12 pc at the distance of M82). Likely additional light echoes reside at a smaller radii of about 0.4 arcsec. The major echo signal corresponds to echoing ma…
We compare the diversity of spectral line velocities in a large sample of type IIb supernovae (SNe IIb) with the expected asphericity in the explosion, as measured from the light echoes of Cassiopeia A (Cas A), which was a historical galactic SN IIb. We revisit the results of Rest et al. (2011a), who used light echoes to observe Cas A from multiple lines of sight and hence determine its asphericity, as seen in the velocity of three spectral lines (He I $λ$5876, H$α$ and the Ca II NIR triplet). We confirm and improve on this measurement by reproducing the effect of the light echoes in the spect…
We present a multi-band sequence of $Hubble~Space~Telescope$ images documenting the emergence and evolution of multiple light echoes (LEs) linked to the stripped-envelope supernova (SN) 2016adj located in the central dust-lane of Centaurus A. Following point-spread function subtraction, we identify the earliest LE emission associated with a SN at only $+$34 days (d) past the epoch of $B$-band maximum. Additional HST images extending through $+$578 d cover the evolution of LE1 taking the form of a ring, while images taken on $+$1991 d reveals not only LE1, but also segments of a new inner LE ri…
A range of astronomical data indicates that ancient supernovae created the galactic environment of the Sun and sculpted the physical properties of the interstellar medium near the heliosphere. In this paper we review the characteristics of the local interstellar medium that have been affected by supernovae. The kinematics, magnetic field, elemental abundances, and configuration of the nearest interstellar material support the view that the Sun is at the edge of the Loop I superbubble, which has merged into the low density Local Bubble. The energy source for the higher temperature X-ray emittin…
Ghosts of eruptions past: Searching for historical Galactic supernovae using variable thermal dust echoes and machine learning
Columbia University（哥伦比亚大学）；Flatiron Institute（平顿研究所）；California Institute of Technology（加州理工学院）；Space Telescope Science Institute（太空望远镜科学研究所）；Johns Hopkins University（约翰斯·霍普金斯大学）；Massachusetts Institute of Technology（麻省理工学院）
We have observed a complex and continuous change in the integrated pulse profile of PSR B2217+47, manifested as additional components trailing the main peak. These transient components are detected over 6 years at $150$ MHz using the LOw Frequency ARray (LOFAR), but they are not seen in contemporaneous Lovell observations at $1.5$ GHz. We argue that propagation effects in the ionized interstellar medium (IISM) are the most likely cause. The putative structures in the IISM causing the profile variation are roughly half-way between the pulsar and the Earth and have transverse radii $R \sim 30$ A…
We performed three-dimensional magnetohydrodynamic simulations to study the evolution of a supernova remnant (SNR) in a turbulent neutral atomic interstellar medium. The media used as background shares characteristics with the Solar neighbourhood and the SNR has mass and energy similar to those of a Type Ia object. Our initial conditions consist of dense clouds in a diluted medium, with the main difference between simulations being the average magnitude of the magnetic field. We measured amplifications of the magnetic energy of up to 34$\%$ and we generated synthetic maps that illustrate how t…
The circumstellar (CS) environment is key to understanding progenitors of type Ia supernovae (SNe Ia), as well as the origin of a peculiar extinction property toward SNe Ia for cosmological application. It has been suggested that multiple scatterings of SN photons by CS dust may explain the non-standard reddening law. In this paper, we examine the effect of re-emission of SN photons by CS dust in the infrared (IR) wavelength regime. This effect allows the observed IR light curves to be used as a constraint on the position/size and the amount of CS dust. The method was applied to observed near-…
PSR B1508+55 is known to have a single component profile above 300 MHz. However, when we study it at frequencies below 100 MHz using the first station of the Long Wavelength Array, it shows multiple components. These include the main pulse, a precursor, a postcursor, and a trailing component. The separation of the trailing component from the main peak evolves over the course of a three year study. This evolution is likely an effect of the pulse signal getting refracted off an ionized gas cloud (acting as a lens) leading to what appears to be a trailing component in the profile as the pulsar si…
Supernova (SN) 2006gy was a hydrogen-rich core-collapse SN that remains one of the most luminous optical supernovae ever observed. The total energy budget (> 2 x 10^51 erg radiated in the optical alone) poses many challenges for standard SN theory. We present new ground-based near-infrared (NIR) observations of SN 2006gy, as well as a single epoch of Hubble Space Telescope (HST) imaging obtained more than two years after the explosion. Our NIR data taken around peak optical emission show an evolution that is largely consistent with a cooling blackbody, with tentative evidence for a growing NIR…
The colour evolution of reddened Type Ia supernovae can place strong constraints on the location of dust and help address the question of whether the observed extinction stems from the interstellar medium or from circumstellar material surrounding the progenitor. Here we analyse BV photometry of 48 reddened Type Ia supernovae from the literature and estimate the dust location from their $B-V$ colour evolution. We find a time-variable colour excess $E(B-V)$ for 15 supernovae in our sample and constrain dust to distances between 0.013 and 45 pc ($4\times10^{16}-10^{20}$ cm). For the remaining su…
We present an analytical model for light echoes (LEs) coming from circumstellar material (CSM) around Type Ia Supernovae (SNe Ia). Using this model we find two spectral signatures at 4100 Å and 6200 Å that are useful to identify LEs during the Lira law phase (between 35 and 80 days after maximum light) coming from nearby CSM at distances of 0.01-0.25 pc. We analyze a sample of 89 SNe Ia divided in two groups according to their B-V decline rate during the Lira law phase, and search for LEs from CSM interaction in the group of SNe with steeper slopes by comparing their spectra with our LE model.…
We present the discovery of a light echo from SN 2007af, a normal Type Ia supernova (SN Ia) in NGC 5584. Hubble Space Telescope (HST) images taken three years post explosion reveal two separate echoes; an outer echo and extended central region, which we propose as an unresolved inner echo. Multiple images were obtained in the F160W, F350LP, F555W, and F814W using the Wide Field Camera 3. If the outer echo is produced by an interstellar dust sheet perpendicular to the line of sight, it is located ~800 pc in front of the SN. The dust for the inner echo is 0.45 pc < d < 90 pc away from the SN. Th…
X-ray bright quasars might be used to trace dust in the circumgalactic and intergalactic medium through the phenomenon of X-ray scattering, which is observed around Galactic objects whose light passes through a sufficient column of interstellar gas and dust. Of particular interest is the abundance of grey dust larger than 0.1 um, which is difficult to detect at other wavelengths. To calculate X-ray scattering from large grains, one must abandon the traditional Rayleigh-Gans approximation. The Mie solution for the X-ray scattering optical depth of the Universe is ~1%. This presents a great diff…
Blackbody evolution and circumstellar medium properties of broad-lined H-rich superluminous supernovae
National Astronomical Observatory of Japan, National Institutes of Natural Sciences（日本国立天文台）；Weizmann Institute of Science（魏茨曼科学研究所）；The Caltech Optical Observatories, California Institute of Technology（加州理工学院光学观测站）
Supernovae remnants (SNRs) represent a major feedback source from stars on the interstellar medium of galaxies. During the latest stage of supernovae explosions, shock waves produced by the initial blast modify the chemistry of gas and dust, inject kinetic energy in the surroundings, and may alter star formation characteristics. Simultaneously, gamma-ray emission is generated by the interaction between the ambiant medium and the cosmic rays. We study the stellar and interstellar contents of IC443, an evolved shell type SNR at a distance of 1.9 kpc, with an estimated age of 30 kyr. We aim to me…
The diffuse interstellar bands (DIBs) are absorption features observed in optical and near-infrared spectra that are thought to be associated with carbon-rich polyatomic molecules in interstellar gas. However, because the central wavelengths of these bands do not correspond with electronic transitions of any known atomic or molecular species, their nature has remained uncertain since their discovery almost a century ago. Here we report on unusually strong DIBs in optical spectra of the broad-lined Type Ic supernova SN 2012ap that exhibit changes in equivalent width over short (~30 days) timesc…
This review presents the fundamentals of the particle acceleration processes active in interstellar medium (ISM), which are essentially based on the so-called Fermi mechanism theory. More specifically, the review presents here in more details the first order Fermi acceleration process -- also known as diffusive shock acceleration (DSA) mechanism. In this case, acceleration is induced by the interstellar (IS) shock waves. These IS shocks are mainly associated with emission nebulae (HII regions, planetary nebulae and supernova remnants). Among all types of emission nebulae, the strongest shocks …
Type IIP supernovae (SNe IIP) often show relatively high continuum polarization ($\sim 1$\%) in the late phase. This polarization feature is generally believed to be due to an inner aspherical core revealed in the late phase, while this polarization feature can also be contributed by the effect of polarized-scattered echoes by circumstellar (CS) dust around the SN. In this paper, we propose a unique method to distinguish polarization from the SN ejecta and from the light echo. We quantitatively examine wavelength dependence of the polarization created by the scattered echoes for various geomet…
We present a new technique to infer dust locations towards reddened Type Ia supernovae and to help discriminate between an interstellar and a circumstellar origin for the observed extinction. Using Monte Carlo simulations, we show that the time-evolution of the light-curve shape and especially of the colour excess \ebv~places strong constraints on the distance between dust and the supernova. We apply our approach to two highly-reddened Type Ia supernovae for which dust distance estimates are available in the literature: SN 2006X and SN 2014J. For the former, we obtain a time-variable $E(B-V)$ …
We have carried out a spectral analysis of the Suzaku X-ray data in the 0.4-12 keV range toward the shell-type very-high-energy γ-ray supernova remnant RX J1713.7-3946. The aims of this analysis are to estimate detailed X-rays spectral properties at a high angular resolution up to 2 arcmin, and to compare them with the interstellar gas. The X-ray spectrum is non-thermal and used to calculate absorbing column density, photon index, and absorption-corrected X-ray flux. The photon index varies significantly from 2.1 to 2.9. It is shown that the X-ray intensity is well correlated with the photon i…
We describe the propagation of supernova shocks within the surrounding medium, which may be due to mass-loss from the progenitor star. The structure and density profile of the ejected material and surrounding medium are considered. Shock wave interaction with clouds and wind-bubbles, and issues relevant to cosmic rays are briefly discussed.
We analyze the influence of fractal structure of the interstellar matter (ISM) density on the parameter values for the radio surface brightness to diameter ($Σ-D$) relation for supernovae remnants (SNRs). We model a dense ISM as a molecular cloud with fractal density structure. SNRs are modelled as spheres of different radius scattered in the modelled ISM. The surface brightness of the SNRs is calculated from the simple relation $Σ\propto ρ^{0.5}D^{-3.5}$ and also from the parametrized more general form $Σ\propto ρ^ηD^{-β_0}$. Our results demonstrate that empirical $Σ-D$ slopes that are steepe…
We review recent progress in elucidating the relationship between high-energy radiation and the interstellar medium (ISM) in young supernova remnants (SNRs) with ages of $\sim$2000 yr, focusing in particular on RX J1713.7$-$3946 and RCW 86. Both SNRs emit strong nonthermal X-rays and TeV $γ$-rays, and they contain clumpy distributions of interstellar gas that includes both atomic and molecular hydrogen. We find that shock-cloud interactions provide a viable explanation for the spatial correlation between the X-rays and ISM. In these interactions, the supernova shocks hit the typically pc-scale…
We present a comprehensive study of interstellar X-ray extinction using the extensive Chandra supernova remnant archive and use our results to refine the empirical relation between the hydrogen column density and optical extinction. In our analysis, we make use of the large, uniform data sample to assess various systematic uncertainties in the measurement of the interstellar X-ray absorption. Specifically, we address systematic uncertainties that originate from (i) the emission models used to fit supernova remnant spectra, (ii) the spatial variations within individual remnants, (iii) the physi…
The image of planetary nebulae (PN), supernova remnant (SNR) and Eta-Carinae is made by three different physical processes. The first process is the expansion of the shell that can be modeled by the canonical laws of motion in the spherical case and by the momentum conservation when gradients of density are present in the interstellar medium. The quality of the simulations is introduced along one direction as well along many directions. The second process is the diffusion of particles that radiate from the advancing layer. The 3D diffusion from a sphere, the 1D diffusion with drift and 1D rand…
Galactic cosmic rays (CRs) are believed to be accelerated at supernova remnant (SNR) shocks. In the hadronic scenario the TeV gamma-ray emission from SNRs originates from decaying pions that are produced in collisions of the interstellar gas and CRs. Using CR-magnetohydrodynamic simulations, we show that magnetic obliquity-dependent shock acceleration is able to reproduce the observed TeV gamma-ray morphology of SNRs such as Vela Jr. and SN1006 solely by varying the magnetic morphology. This implies that gamma-ray bright regions result from quasi-parallel shocks (i.e., when the shock propagate…
Type IIP supernovae (SNe IIP) are the most common class of core-collapse SNe. They often show rapid increase of polarization degree in the late phase. This time evolution is generally believed to originate from the emergence of an inner aspherical core, while an effect of polarized-scattered echoes by circumstellar (CS) dust around the SN may also substantially contribute to this polarization feature. In this study, we examine the effects of the scatted echoes on the SN polarization through radiative transfer simulations for various geometry and amount of CS dust. It has been found that asymme…
Some highly reddened Type Ia supernovae (SNe Ia) display low total-to-selective extinction ratios ($R_V \lesssim 2$) in comparison to that of typical Milky Way dust ($R_V \approx 3.3$), and polarization curves that rise steeply to blue wavelengths, with peak polarization values at short wavelengths ($λ_{\rm max} < 0.4$ $μ$m) in comparison to the typical Galactic values ($λ_{\rm max} \approx 0.55$ $μ$m). Understanding the source of these properties could provide insight into the progenitor systems of SNe Ia. We aim to determine whether they are the result of the host galaxy's interstellar dust …
In this paper we report the results of the first $\sim$four years of spectroscopic and photometric monitoring of the Type IIn supernova SN 2015da (also known as PSN J13522411+3941286, or iPTF16tu). The supernova exploded in the nearby spiral galaxy NGC 5337 in a relatively highly extinguished environment. The transient showed prominent narrow Balmer lines in emission at all times and a slow rise to maximum in all bands. In addition, early observations performed by amateur astronomers give a very well-constrained explosion epoch. The observables are consistent with continuous interaction betwee…
Frequent supernova explosions in compact starburst regions are a main shaper of these regions' interstellar media (ISM). In most starbursts, the supernova remnants blast open a hot phase that fills the regions and launches a superwind. Denser starbursts are too overpressured for hot wind formation, but supernovae still stir up the ISM. I argue that supernovae power ubiquitous turbulence through each of the starburst ISM phases, including the hot wind, and that a fluctuation dynamo amplifies magnetic fields until they are in equipartition with the turbulence. Supernovae can drive turbulence wit…
RX J1713.7-3946 is the most remarkable very-high-energy γ-ray supernova remnant which emits synchrotron X-rays without thermal features. We made a comparative study of CO, HI and X-rays in order to better understand the relationship between the X-rays, and the molecular and atomic gas. The results indicate that the X-rays are enhanced around the CO and HI clumps on a pc scale but are decreased inside the clumps on a 0.1 pc scale. Magnetohydrodynamic numerical simulations of the shock interaction with molecular and atomic gas indicate that the interaction between the shock waves and the clumps …
In our ongoing study of eta Carinae's light echoes, there is a relatively bright echo that has been fading slowly, reflecting the 1845-1858 plateau of the eruption. A separate paper discusses its detailed evolution, but here we highlight one important result: the H-alpha line shows extremely broad emission wings that reach -10,000km/s to the blue and +20,000km/s to the red. The line profile shape is inconsistent with electron scattering wings, indicating high-velocity outflowing material. These are the fastest outflow speeds ever seen in a non-terminal massive star eruption. The broad wings ar…
Observations have demonstrated that supernovae efficiently produce dust. This is consistent with the hypothesis that supernovae and asymptotic giant branch stars are the primary producers of dust in the Universe. However, there has been a longstanding question of how much of the dust detected in the interiors of young supernova remnants can escape into the interstellar medium. We present new hydrodynamical calculations of the evolution of dust grains that were formed in dense ejecta clumps within a Cas A-like remnant. We follow the dynamics of the grains as they decouple from the gas after the…
An analysis of the energy spectra of cosmic rays and particularly the precise data from the AMS-02 experiment support the view about the important role of the Local Bubble in the nearby interstellar medium. It is suggested that the bulk of cosmic rays below about 200 GV of rigidity (momentum/charge ratio) comes from the modest number of supernova remnants in the Local Bubble which appear to have occurred some $10^6$ years ago and contributed to its formation. At higher rigidities the contribution from a 'Local Source', a single supernova remnant generated some $10^5$ years ago seems to dominat…
Supernova remnants (SNRs) are one of the most energetic astrophysical events and are thought to be the dominant source of Galactic cosmic rays (CRs). A recent report on observations from the Fermi satellite has shown a signature of pion decay in the gamma-ray spectra of SNRs. This provides strong evidence that high-energy protons are accelerated in SNRs. The actual gamma-ray emission from pion decay should depend on the diffusion of CRs in the interstellar medium. In order to quantitatively analyse the diffusion of high-energy CRs from acceleration sites, we have performed test particle numeri…
We report on the results from our measurements of the interstellar medium (ISM) abundances for the elements O, Ne, Mg, Si, and Fe in the Large Magellanic Cloud (LMC). We used the archival Chandra data for sixteen supernova remnants (SNRs) in the LMC (0453--68.5, DEM L71, N23, 0519--69.0, N49B, N132D, N49, N206, 0534--69.9, DEM L238, N63A, Honeycomb, N157B, 0540--69.3, DEM L316B, and 0548--70.4). Our results represent LMC abundance measurements based on the modern Chandra data. We place tight constraints on our measured elemental abundances and find lower abundances than previous measurements b…
The mixed morphology class of supernova remnants has centrally peaked X-ray emission along with a shell-like morphology in radio emission. White & Long proposed that these remnants are evolving in a cloudy medium wherein the clouds are evaporated via thermal conduction once being overrun by the expanding shock. Their analytical model made detailed predictions regarding temperature, density and emission profiles as well as shock evolution. We present numerical hydrodynamical models in 2D and 3D including thermal conduction, testing the White & Long model and presenting results for the evolution…
A cool phase of the interstellar medium has been observed in many giant elliptical galaxies, but its origin remains unclear. We propose that uneven heating from Type Ia supernovae (SNe Ia), together with radiative cooling, can lead to the formation of the cool phase. The basic idea is that since SNe Ia explode randomly, gas parcels which are not directly heated by SN shocks will cool, forming multiphase gas. We run a series of idealized high-resolution numerical simulations, and find that cool gas develops even when the overall SNe heating rate $H$ exceeds the cooling rate $C$ by a factor as l…
The soft gamma repeater SGR 1806-20 is most famous for its giant flare from 2004, which yielded the highest gamma-ray flux ever observed on Earth. The flare emphasized the importance of determining the distance to the SGR, thus revealing the flare's energy output, with implications on SGRs energy budget and giant flare rates. We analyze x-ray scattering echoes observed by Swift/XRT following the 2006 August 6 intermediate burst of SGR 1806-20. Assuming positions and opacities of the molecular clouds along the line-of-sight from previous works, we derive direct constrains on the distance to SGR…
Supernovae (SN), the most energetic stellar feedback mechanism, are crucial for regulating the interstellar medium (ISM) and launching galactic winds. We explore how supernova remnants (SNRs) create a multiphase medium by performing 3D hydrodynamical simulations at various SN rates, $S$, and ISM average densities, $\bar{n}$. The evolution of a SNR in a self-consistently generated three-phase ISM is qualitatively different from that in a uniform or a two-phase warm/cold medium. By travelling faster and further in the low-density hot phase, the domain of a SNR increases by $>10^{2.5}$. Varying $…
The size distribution of supernova remnants (SNRs) can help to clarify the various aspects of their evolution and interaction with the interstellar medium (ISM). Since the observed samples of SNRs are a collection of objects with very different ages and origin that evolve in different conditions of the ISM, statistical Monte Carlo methods can be used to model their statistical distributions. Based on very general assumptions on the evolution, we have modeled samples of SNRs at various initial and environmental conditions, which were then compared with observed collections of SNRs. In the evolu…
Using three-dimensional magnetohydrodynamics simulations, we show that the efficiency of cosmic-ray (CR) production at supernova remnants (SNRs) is over-predicted if it could be estimated based on proper motion measurements of H$α$ filaments in combination with shock-jump conditions. Density fluctuations of upstream medium make shock waves rippled and oblique almost everywhere. The kinetic energy of the shock wave is transferred into that of downstream turbulence as well as thermal energy which is related to the shock velocity component normal to the shock surface. Our synthetic observation sh…
For Type Ia supernovae (SNe Ia) observed through a non-uniform interstellar medium (ISM) in its host galaxy, we investigate whether the non-uniformity can cause observable time variations in dust extinction and in gas absorption due to the expansion of the SN photosphere with time. We show that, owing to the steep spectral index of the ISM density power spectrum, sizable density fluctuation amplitudes at the length scale of typical ISM structures ($\gtrsim \text{ 10 pc}$) will translate to much smaller fluctuations on the scales of a SN photosphere. Therefore the typical amplitude of time vari…
Interstellar clouds can act as target material for hadronic cosmic rays; gamma rays subsequently produced through inelastic proton-proton collisions and spatially associated with such clouds can provide a key indicator of efficient particle acceleration. However, even in the case that particle acceleration proceeds up to PeV energies, the system of accelerator and nearby target material must fulfil a specific set of conditions in order to produce a detectable gamma-ray flux. In this study, we rigorously characterise the necessary properties of both cloud and accelerator. By using available Sup…
We present Spitzer observations at 3.6 and 4.5um of the supernova SN2011dh (PTF11eon) in M51 from 18 days to 625 days after explosion. The mid-infrared emission peaks at 24 days after explosion at a few times 10^7 Lsun, and decays more slowly than the visible-light bolometric luminosity. The infrared color temperature cools for the first 90 days and then is constant. Simple numerical models of a thermal echo can qualitatively reproduce the early behavior. At late times, the mid-IR light curve cannot be explained by a simple thermal echo model, suggesting additional dust heating or line emissio…
Axions are a theoretically promising dark matter (DM) candidate. In the presence of radiation from bright astrophysical sources at radio frequencies, nonrelativistic DM axions can undergo stimulated decay to two nearly back-to-back photons, meaning that bright sources of radio waves will have a counterimage ("gegenschein") in nearly the exact opposite spatial direction. The counterimage will be spectrally distinct from backgrounds, taking the form of a narrow radio line centered at $ν= m_a/4π$ with a width determined by Doppler broadening in the DM halo, $Δν/ν\sim 10^{-3}$. In this work, we sh…
Here we present three-dimensional high resolution simulations of Type Ia supernova in the presence of a non-degenerate companion. We find that the presence of a nearby companion leaves a long-lived hole in the supernova ejecta. In particular, we aim to study the long term evolution of this hole as the supernova ejecta interacts with the surrounding interstellar medium. Using estimates for the x-ray emission, we find that the hole generated by the companion remains for many centuries after the interaction between the ejecta and the interstellar medium. We also show that the hole is discernible …
The study of both supernova remnants and the hot and cold phases of the interstellar medium are essential for understanding the final stages of stellar evolution and their feedback on the evolution of galaxies through injection of energy and heavy elements. These studies are also crucial for understanding the physics of supernovae, their cosmological implication, and the origin of galactic cosmic rays. The unique capabilities of Athena+ will allow us to explore a new parameter space. Spatially-resolved high-resolution spectroscopy using Athena+ X-IFU of young remnants will allow to characteriz…
