Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userSN 2013aa and SN 2017cbv: Two Sibling Type Ia Supernovae in the spiral galaxy NGC 5643
80
0
0.0
(
0
)
Added by
Christopher R. Burns
Publication date
2020
fields
Physics
and research's language is
English
Ask ChatGPT about the research
No Arabic abstract
We present photometric and spectroscopic observations of SN 2013aa and SN 2017cbv, two nearly identical type Ia supernovae (SNe Ia) in the host galaxy NGC 5643. The optical photometry has been obtained using the same telescope and instruments used by the Carnegie Supernova Project. This eliminates most instrumental systematics and provides light curves in a stable and well-understood photometric system. Having the same host galaxy also eliminates systematics due to distance and peculiar velocity, providing an opportunity to directly test the relative precision of SNe Ia as standard candles. The two SNe have nearly identical decline rates, negligible reddening, and remarkably similar spectra and, at a distance of $sim 20$ Mpc, are ideal as potential calibrators for the absolute distance using primary indicators such as Cepheid variables. We discuss to what extent these two SNe can be considered twins and compare them with other supernova siblings in the literature and their likely progenitor scenarios. Using 12 galaxies that hosted 2 or more SNe~Ia, we find that when using SNe~Ia, and after accounting for all sources of observational error, one gets consistency in distance to 3 percent.
rate research
Read More
We present deep Chandra X-ray observations of two nearby Type Ia supernovae, SN 2017cbv and SN 2020nlb, which reveal no X-ray emission down to a luminosity $L_X$$lesssim$5.3$times$10$^{37}$ and $lesssim$5.4$times$10$^{37}$ erg s$^{-1}$ (0.3--10 keV), respectively, at $sim$16--18 days after the explosion. With these limits, we constrain the pre-explosion mass-loss rate of the progenitor system to be $dot{M}$$<$7.2$times$10$^{-9}$ and $<$9.7$times$10$^{-9}$ M$_{odot}$ yr$^{-1}$ for each (at a wind velocity $v_w$=100 km s$^{-1}$ and a radius of $R$$approx$10$^{16}$ cm), assuming any X-ray emission would originate from inverse Compton emission from optical photons up-scattered by the supernova shock. If the supernova environment was a constant density medium, we find a number density limit of n$_{CSM}$$<$36 and $<$65 cm$^{-3}$, respectively. These X-ray limits rule out all plausible symbiotic progenitor systems, as well as large swathes of parameter space associated with the single degenerate scenario, such as mass loss at the outer Lagrange point and accretion winds. We also present late-time optical spectroscopy of SN 2020nlb, and set strong limits on any swept up hydrogen ($L_{Halpha}$$<$2.7$times$10$^{37}$ ergs s$^{-1}$) and helium ($L_{He, lambda 6678}$$<$2.7$times$10$^{37}$ ergs s$^{-1}$) from a nondegenerate companion, corresponding to $M_{H}$$lesssim$0.7--2$times$10$^{-3}$ M$_{odot}$ and $M_{He}$$lesssim$4$times$10$^{-3}$ M$_{odot}$. Radio observations of SN 2020nlb at 14.6 days after explosion also yield a non-detection, ruling out most plausible symbiotic progenitor systems. While we have doubled the sample of normal type Ia supernovae with deep X-ray limits, more observations are needed to sample the full range of luminosities and sub-types of these explosions, and set statistical constraints on their circumbinary environments.
We present an analysis of ultraviolet (UV) to near-infrared observations of the fast-declining Type Ia supernovae (SNe Ia) 2007on and 2011iv, hosted by the Fornax cluster member NGC 1404. The B-band light curves of SN 2007on and SN 2011iv are characterised by dm_15(B) decline-rate values of 1.96 mag and 1.77 mag, respectively. Although they have similar decline rates, their peak B- and H-band magnitudes differ by ~0.60 mag and ~0.35 mag, respectively. After correcting for the luminosity vs. decline rate and the luminosity vs. colour relations, the peak B-band and H-band light curves provide distances that differ by ~14% and ~9%, respectively. These findings serve as a cautionary tale for the use of transitional SNe Ia located in early-type hosts in the quest to measure cosmological parameters. Interestingly, even though SN 2011iv is brighter and bluer at early times, by three weeks past maximum and extending over several months, its B-V colour is 0.12 mag redder than that of SN 2007on. To reconcile this unusual behaviour, we turn to guidance from a suite of spherical one-dimensional Chandrasekhar-mass delayed-detonation explosion models. In this context, 56Ni production depends on both the so-called transition density and the central density of the progenitor white dwarf. To first order, the transition density drives the luminosity-width relation, while the central density is an important second-order parameter. Within this context, the differences in the B-V color evolution along the Lira regime suggests the progenitor of SN~2011iv had a higher central density than SN~2007on.
The Type Ia supernova (SN Ia) SN 2000cx was one of the most peculiar transients ever discovered, with a rise to maximum brightness typical of a SN Ia, but a slower decline and a higher photospheric temperature. Thirteen years later SN 2013bh (aka iPTF13abc), a near identical twin, was discovered and we obtained optical and near-IR photometry and low-resolution optical spectroscopy from discovery until about 1 month past r-band maximum brightness. The spectra of both objects show iron-group elements (Co II, Ni II, Fe II, Fe III, and high-velocity features [HVFs] of Ti II), intermediate-mass elements (Si II, Si III, and S II), and separate normal velocity features (~12000 km/s) and HVFs (~24000 km/s) of Ca II. Persistent absorption from Fe III and Si III, along with the colour evolution, imply high blackbody temperatures for SNe 2013bh and 2000cx (~12000 K). Both objects lack narrow Na I D absorption and exploded in the outskirts of their hosts, indicating that the SN environments were relatively free of interstellar or circumstellar material and may imply that the progenitors came from a relatively old and low-metallicity stellar population. Models of SN 2000cx, seemingly applicable to SN 2013bh, imply the production of up to ~1 M_Sun of Ni-56 and (4.3-5.5)e-3 M_Sun of fast-moving Ca ejecta.
We have been searching for surviving companions of progenitors of Galactic Type-Ia supernovae, in particular SN 1572 and SN 1006. These companion stars are expected to show peculiarities: (i) to be probably more luminous than the Sun, (ii) to have high radial velocity and proper motion, (iii) to be possibly enriched in metals from the SNIa ejecta, and (iv) to be located at the distance of the SNIa remnant. We have been characterizing possible candidate stars using high-resolution spectroscopic data taken at 10m-Keck and 8.2m-VLT facilities. We have identified a very promising candidate companion (Tycho G) for SN 1572, but we have not found any candidate companion for SN 1006, suggesting that SN event occurred in 1006 could have been the result of the merging of two white dwarfs. Adding these results to the evidence from the other direct searches, the clear minority of cases (20% or less) seem to disfavour the single-degenerate channel or that preferentially the single-degenerate escenario would involve main-sequence companions less massive than the Sun. Therefore, it appears to be very important to continue investigating these and other Galactic Type-Ia SNe such as the Johannes Kepler SN 1604.
SN 2011fe is the nearest supernova of Type Ia (SN Ia) discovered in the modern multi-wavelength telescope era, and it also represents the earliest discovery of a SN Ia to date. As a normal SN Ia, SN 2011fe provides an excellent opportunity to decipher long-standing puzzles about the nature of SNe Ia. In this review, we summarize the extensive suite of panchromatic data on SN 2011fe, and gather interpretations of these data to answer four key questions: 1) What explodes in a SN Ia? 2) How does it explode? 3) What is the progenitor of SN 2011fe? and 4) How accurate are SNe Ia as standardizeable candles? Most aspects of SN 2011fe are consistent with the canonical picture of a massive CO white dwarf undergoing a deflagration-to-detonation transition. However, there is minimal evidence for a non-degenerate companion star, so SN 2011fe may have marked the merger of two white dwarfs.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
