scholarly journals Forbidden Line Emission from Type Ia Supernova Remnants Containing Balmer-dominated Shells

2021 ◽  
Vol 923 (2) ◽  
pp. 141
Author(s):  
Chuan-Jui Li ◽  
You-Hua Chu ◽  
John C. Raymond ◽  
Bruno Leibundgut ◽  
Ivo R. Seitenzahl ◽  
...  
Keyword(s):  
Supernova Remnants ◽  
Hubble Space Telescope ◽  
Line Emission ◽  
Physical Property ◽  
Cosmic Ray ◽  
Neutral Medium ◽  
Wide Field ◽  
Type Ia ◽  
Shock Precursor ◽  
Ia Supernovae

Abstract Balmer-dominated shells in supernova remnants (SNRs) are produced by collisionless shocks advancing into a partially neutral medium and are most frequently associated with Type Ia supernovae. We have analyzed Hubble Space Telescope (HST) images and Very Large Telescope (VLT)/Multi-Unit Spectroscopic Explorer (MUSE) or AAT/Wide Field Integral Spectrograph observations of five Type Ia SNRs containing Balmer-dominated shells in the LMC: 0509–67.5, 0519–69.0, N103B, DEM L71, and 0548–70.4. Contrary to expectations, we find bright forbidden-line emission from small dense knots embedded in four of these SNRs. The electron densities in some knots are higher than 104 cm−3. The size and density of these knots are not characteristic for interstellar medium—they most likely originate from a circumstellar medium ejected by the SN progenitor. Physical property variations of dense knots in the SNRs appear to reflect an evolutionary effect. The recombination timescales for high densities are short, and HST images of N103B taken 3.5 yr apart already show brightness changes in some knots. VLT/MUSE observations detect [Fe xiv] line emission from reverse shocks into SN ejecta as well as forward shocks into the dense knots. Faint [O iii] line emission is also detected from the Balmer shell in 0519–69.0, N103B, and DEM L71. We exclude the postshock origin because the [O iii] line is narrow. For the preshock origin, we considered three possibilities: photoionization precursor, cosmic-ray precursor, and neutral precursor. We conclude that the [O iii] emission arises from oxygen that has been photoionized by [He ii] λ304 photons and is then collisionally excited in a shock precursor heated mainly by cosmic rays.

scholarly journals Hubble Space Telescope observations of Europa in and out of eclipse

2010 ◽  
Vol 9 (4) ◽  
pp. 265-271 ◽  
Author(s):  
W.B. Sparks ◽  
M. McGrath ◽  
K. Hand ◽  
H.C. Ford ◽  
P. Geissler ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Broad Band ◽  
Line Emission ◽  
Optical Emission ◽  
High Energy ◽  
High Energy Particle ◽  
Wide Field ◽  
Particle Radiation ◽  
Space Telescope ◽  
Solar Blind

AbstractEuropa is a prime target for astrobiology and has been prioritized as the next target for a National Aeronautics and Space Administration flagship mission. It is important, therefore, that we advance our understanding of Europa, its ocean and physical environment as much as possible. Here, we describe observations of Europa obtained during its orbital eclipse by Jupiter using the Hubble Space Telescope. We obtained Advanced Camera for Surveys Solar Blind Channel far ultraviolet low-resolution spectra that show oxygen line emission both in and out of eclipse. We also used the Wide-Field and Planetary Camera-2 and searched for broad-band optical emission from fluorescence of the surface material, arising from the very high level of incident energetic particle radiation on ices and potentially organic substances. The high-energy particle radiation at the surface of Europa is extremely intense and is responsible for the production of a tenuous oxygen atmosphere and associated FUV line emission. Approximately 50% of the oxygen emission lasts at least a few hours into the eclipse. We discuss the detection limits of the optical emission, which allow us to estimate the fraction of incident energy reradiated at optical wavelengths, through electron-excited emission, Cherenkov radiation in the ice and fluorescent processes.

scholarly journals Identification of Type Ia Supernovae at Redshift 1.3 and Beyond with the Advanced Camera for Surveys on the Hubble Space Telescope

2004 ◽  
Vol 600 (2) ◽  
pp. L163-L166 ◽  
Author(s):  
Adam G. Riess ◽  
Louis-Gregory Strolger ◽  
John Tonry ◽  
Zlatan Tsvetanov ◽  
Stefano Casertano ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Type Ia Supernovae ◽  
Space Telescope ◽  
Type Ia ◽  
Advanced Camera For Surveys ◽  
Ia Supernovae

scholarly journals Nonlinear diffusion of cosmic rays escaping from supernova remnants: Cold partially neutral atomic and molecular phases

2020 ◽  
Vol 633 ◽  
pp. A72 ◽  
Author(s):  
L. Brahimi ◽  
A. Marcowith ◽  
V. S. Ptuskin
Keyword(s):  
Cosmic Rays ◽  
Supernova Remnants ◽  
Cosmic Ray ◽  
Alfven Wave ◽  
Nonlinear Propagation ◽  
Neutral Medium ◽  
Streaming Instability ◽  
Weakly Ionized ◽  
Two Phases ◽  
Multi Phase

Aims. We aim to elucidate cosmic ray (CR) propagation in the weakly ionized environments of supernova remnants (SNRs) basing our analysis on the cosmic ray cloud (CRC) model. Methods. We solved two transport equations simultaneously: one for the CR pressure and one for the Alfvén wave energy density where CRs are initially confined in the SNR shock. Cosmic rays trigger a streaming instability and produce slab-type resonant Alfvén modes. The self-generated turbulence is damped by ion-neutral collisions and by noncorrelated interaction with Alfvén modes generated at large scales. Results. We show that CRs leaking in cold dense phases such as those found in cold neutral medium (CNM) and diffuse molecular medium (DiM) can still be confined over distances of a few tens of parsecs from the CRC center for a few thousand years. At 10 TeV, CR diffusion can be suppressed by two or three orders of magnitude. This effect results from a reduced ion-neutral collision damping in the decoupled regime. We calculate the grammage of CRs in these environments. We find that in both single and multi-phase setups at 10 GeV, CNM and DiM media can produce grammage in the range 10–20 g cm−2 in the CNM and DiM phases. At 10 TeV, because of nonlinear propagation the grammage increases to values in the range 0.5–20 g cm−2 in these two phases. We also present preliminary calculations in inhomogeneous interstellar medium combining two or three different phases where we obtain the same trends.

scholarly journals Verifying the Use of Supernovae as Probes of the Cosmic Expansion

2005 ◽  
Vol 201 ◽  
pp. 231-240
Author(s):  
Richard Ellis ◽  
Mark Sullivan
Keyword(s):  
Large Range ◽  
Hubble Space Telescope ◽  
Light Curves ◽  
Host Galaxy ◽  
Hubble Diagram ◽  
Galaxy Type ◽  
Significant Difference ◽  
Type Ia ◽  
Ia Supernovae

We present preliminary results of a follow-up survey which aims to characterise in detail those galaxies which hosted Type Ia supernovae found by the Supernova Cosmology Project. Our survey has two components: Hubble Space Telescope imaging with STIS and Keck spectroscopy with ESI, the goal being to classify each host galaxy into one of three broad morphological/spectral classes and hence to investigate the dependence of supernovae properties on host galaxy type over a large range in redshift. Of particular interest is the supernova Hubble diagram characterised by host galaxy class which suggests that most of the scatter arises from those occurring in late-type irregulars. Supernovae hosted by (presumed dust-free) E/SO galaxies closely follow the adopted SCP cosmological model. Although larger datasets are required, we cannot yet find any significant difference in the light curves of distant supernovae hosted in different galaxy types.

scholarly journals 16O(p,α)13N makes explosive oxygen burning sensitive to the metallicity of the progenitors of type Ia supernovae

2019 ◽  
Vol 627 ◽  
pp. A146
Author(s):  
E. Bravo
Keyword(s):  
Supernova Remnants ◽  
Fusion Reaction ◽  
Reaction Rates ◽  
Type Ia Supernovae ◽  
Fusion Reactions ◽  
Maximum Brightness ◽  
Theoretical Predictions ◽  
Type Ia ◽  
Standard Values ◽  
Ia Supernovae

Even though the main nucleosynthetic products of type Ia supernovae belong to the iron-group, intermediate-mass alpha-nuclei (silicon, sulfur, argon, and calcium) stand out in their spectra up to several weeks past maximum brightness. Recent measurements of the abundances of calcium, argon, and sulfur in type Ia supernova remnants have been interpreted in terms of metallicity-dependent oxygen burning, in accordance with previous theoretical predictions. It is known that α-rich oxygen burning results from 16O→12C followed by efficient 12C+12C fusion reaction, as compared to oxygen consumption by 16O fusion reactions, but the precise mechanism of dependence on the progenitor metallicity has remained unidentified so far. I show that the chain 16O(p,α)13N(γ,p)12C boosts α-rich oxygen burning when the proton abundance is large, increasing the synthesis of argon and calcium with respect to sulfur and silicon. For high-metallicity progenitors, the presence of free neutrons leads to a drop in the proton abundance and the above chain is not efficient. Although the rate of 16O(p,α)13N can be found in astrophysical reaction rate libraries, its uncertainty is unconstrained. Assuming that all reaction rates other than 16O(p,α)13N retain their standard values, an increase by a factor of approximately seven of the 16O(p,α)13N rate at temperatures in the order 3−5 × 109 K is enough to explain the whole range of calcium-to-sulfur mass ratios measured in Milky Way and LMC supernova remnants. These same measurements provide a lower limit to the 16O(p,α)13N rate in the mentioned temperature range, on the order of a factor of 0.5 with respect to the rate reported in widely used literature tabulations.

scholarly journals Searching for supernovae in the multiply-imaged galaxies behind the gravitational telescope A370

2018 ◽  
Vol 614 ◽  
pp. A103 ◽  
Author(s):  
T. Petrushevska ◽  
A. Goobar ◽  
D. J. Lagattuta ◽  
R. Amanullah ◽  
L. Hangard ◽  
...  
Keyword(s):  
Time Delays ◽  
Near Infrared ◽  
High Redshift ◽  
Formation Rate ◽  
Galaxy Cluster ◽  
Wide Field ◽  
Space Telescope ◽  
Multiple Images ◽  
Type Ia ◽  
Ia Supernovae

Aims. Strong lensing by massive galaxy clusters can provide magnification of the flux and even multiple images of the galaxies that lie behind them. This phenomenon facilitates observations of high-redshift supernovae (SNe) that would otherwise remain undetected. Type Ia supernovae (SNe Ia) detections are of particular interest because of their standard brightness, since they can be used to improve either cluster lensing models or cosmological parameter measurements. Methods. We present a ground-based, near-infrared search for lensed SNe behind the galaxy cluster Abell 370. Our survey was based on 15 epochs of J-band observations with the HAWK-I instrument on the Very Large Telescope (VLT). We use Hubble Space Telescope (HST) photometry to infer the global properties of the multiply-imaged galaxies. Using a recently published lensing model of Abell 370, we also present the predicted magnifications and time delays between the images. Results. In our survey, we did not discover any live SNe from the 13 lensed galaxies with 47 multiple images behind Abell 370. This is consistent with the expectation of 0.09 ± 0.02 SNe calculated based on the measured star formation rate. We compare the expectations of discovering strongly lensed SNe in our survey and that performed with HST during the Hubble Frontier Fields (HFF) programme. We also show the expectations of search campaigns that can be conducted with future facilities, such as the James Webb Space Telescope (JWST) or the Wide-Field Infrared Survey Telescope (WFIRST). We show that the NIRCam instrument aboard the JWST will be sensitive to most SN multiple images in the strongly lensed galaxies and thus will be able to measure their time delays if observations are scheduled accordingly.

scholarly journals HUBBLE SPACE TELESCOPE STUDIES OF NEARBY TYPE Ia SUPERNOVAE: THE MEAN MAXIMUM LIGHT ULTRAVIOLET SPECTRUM AND ITS DISPERSION

2011 ◽  
Vol 727 (2) ◽  
pp. L35 ◽  
Author(s):  
Jeff Cooke ◽  
Richard S. Ellis ◽  
Mark Sullivan ◽  
Peter Nugent ◽  
D. Andrew Howell ◽  
...  
Keyword(s):  
Hubble Space Telescope ◽  
Ultraviolet Spectrum ◽  
Type Ia Supernovae ◽  
Space Telescope ◽  
Maximum Light ◽  
Type Ia ◽  
The Mean ◽  
Ia Supernovae

scholarly journals An Algorithm for Real-Time Optimal Photocurrent Estimation Including Transient Detection for Resource-Constrained Imaging Applications

2016 ◽  
Vol 05 (03) ◽  
pp. 1650007
Author(s):  
Michael Zemcov ◽  
Brendan Crill ◽  
Matthew Ryan ◽  
Zak Staniszewski
Keyword(s):  
Linear Models ◽  
Hubble Space Telescope ◽  
Cosmic Ray ◽  
Low Earth Orbit ◽  
Earth Orbit ◽  
Wide Field ◽  
Resource Constrained ◽  
Ir Detectors ◽  
Sensing Applications ◽  
Near Ir

Mega-pixel charge-integrating detectors are common in near-IR imaging applications. Optimal signal-to-noise ratio estimates of the photocurrents, which are particularly important in the low-signal regime, are produced by fitting linear models to sequential reads of the charge on the detector. Algorithms that solve this problem have a long history, but can be computationally intensive. Furthermore, the cosmic ray background is appreciable for these detectors in Earth orbit, particularly above the Earth’s magnetic poles and the South Atlantic Anomaly, and on-board reduction routines must be capable of flagging affected pixels. In this paper, we present an algorithm that generates optimal photocurrent estimates and flags random transient charge generation from cosmic rays, and is specifically designed to fit on a computationally restricted platform. We take as a case study the Spectro-Photometer for the History of the Universe, Epoch of Reionization, and Ices Explorer (SPHEREx), a NASA Small Explorer astrophysics experiment concept, and show that the algorithm can easily fit in the resource-constrained environment of such a restricted platform. Detailed simulations of the input astrophysical signals and detector array performance are used to characterize the fitting routines in the presence of complex noise properties and charge transients. We use both Hubble Space Telescope Wide Field Camera-3 and Wide-field Infrared Survey Explorer to develop an empirical understanding of the susceptibility of near-IR detectors in low earth orbit and build a model for realistic cosmic ray energy spectra and rates. We show that our algorithm generates an unbiased estimate of the true photocurrent that is identical to that from a standard line fitting package, and characterize the rate, energy, and timing of both detected and undetected transient events. This algorithm has significant potential for imaging with charge-integrating detectors in astrophysics, earth science, and remote sensing applications.

scholarly journals The Interaction of Type Ia Supernovae with Planetary Nebulae: The Case of Kepler’s Supernova Remnant

Galaxies ◽  
2020 ◽  
Vol 8 (2) ◽  
pp. 38
Author(s):  
A. Chiotellis ◽  
P. Boumis ◽  
Z. T. Spetsieri
Keyword(s):  
Supernova Remnants ◽  
Ambient Medium ◽  
Planetary Nebulae ◽  
Northern Region ◽  
Type Ia Supernovae ◽  
Type Ia ◽  
Partial Interaction ◽  
Ia Supernovae ◽  
Progenitor Stars ◽  
Good Agreement

One of the key methods for determining the unknown nature of Type Ia supernovae (SNe Ia) is the search for traces of interaction between the SN ejecta and the circumstellar structures at the resulting supernova remnants (SNRs Ia). So far, the observables that we receive from well-studied SNRs Ia cannot be explained self-consistently by any model presented in the literature. In this study, we suggest that the circumstellar medium (CSM) being observed to surround several SNRs Ia was mainly shaped by planetary nebulae (PNe) that originated from one or both progenitor stars. Performing two-dimensional hydrodynamic simulations, we show that the ambient medium shaped by PNe can account for several properties of the CSM that have been found to surround SNe Ia and their remnants. Finally, we model Kepler’s SNR considering that the SN explosion occurred inside a bipolar PN. Our simulations show good agreement with the observed morphological and kinematic properties of Kepler’s SNR. In particular, our model reproduces the current expansion parameter of Kepler’s SNR, the partial interaction of the remnant with a dense CSM at its northern region and finally the existence of two opposite protrusions (‘ears’) at the equatorial plane of the SNR.

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