Download or read book Rates and Progenitors of Type Ia Supernovae written by and published by . This book was released on 2004 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt: The remarkable uniformity of Type Ia supernovae has allowed astronomers to use them as distance indicators to measure the properties and expansion history of the Universe. However, Type Ia supernovae exhibit intrinsic variation in both their spectra and observed brightness. The brightness variations have been approximately corrected by various methods, but there remain intrinsic variations that limit the statistical power of current and future observations of distant supernovae for cosmological purposes. There may be systematic effects in this residual variation that evolve with redshift and thus limit the cosmological power of SN Ia luminosity-distance experiments. To reduce these systematic uncertainties, we need a deeper understanding of the observed variations in Type Ia supernovae. Toward this end, the Nearby Supernova Factory has been designed to discover hundreds of Type Ia supernovae in a systematic and automated fashion and study them in detail. This project will observe these supernovae spectrophotometrically to provide the homogeneous high-quality data set necessary to improve the understanding and calibration of these vital cosmological yardsticks. From 1998 to 2003, in collaboration with the Near-Earth Asteroid Tracking group at the Jet Propulsion Laboratory, a systematic and automated searching program was conceived and executed using the computing facilities at Lawrence Berkeley National Laboratory and the National Energy Research Supercomputing Center. An automated search had never been attempted on this scale. A number of planned future large supernovae projects are predicated on the ability to find supernovae quickly, reliably, and efficiently in large datasets. A prototype run of the SNfactory search pipeline conducted from 2002 to 2003 discovered 83 SNe at a final rate of 12 SNe/month. A large, homogeneous search of this scale offers an excellent opportunity to measure the rate of Type Ia supernovae. This thesis presents a new method for analyzing the true sensitivity of a multi-epoch supernova search and finds a Type Ia supernova rate from z (almost equal to) 0.01-0.1 of r{sub V} = 4.26{sub -1.93 -0.10}{sup +1.39 +0.10} h3 x 10−4 SNe Ia/yr/Mpc3 from a preliminary analysis of a subsample of the SNfactory prototype search. Several unusual supernovae were found in the course of the SNfactory prototype search. One in particular, SN 2002ic, was the first SN Ia to exhibit convincing evidence for a circumstellar medium and offers valuable insight into the progenitors of Type Ia supernovae.
Download or read book Rates and Progenitors of Type 1a Supernovae written by William Michael Wood-Vasey and published by . This book was released on 2004 with total page 600 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Type Ia Supernovae written by Epson Thiago Masikiv Heringer and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Thermonuclear (Type Ia) supernovae are excellent distance indicators, due to their uniform peak brightness. They are also important contributors to the chemical evolution of galaxies since their explosions supply large amounts of iron peak elements to the interstellar medium. However, there is no consensus on the progenitor systems of these supernovae. As a result, different delay times from the formation of the binary system to the supernova have been proposed. Whether the observed rate of supernova Type Ia in early-type galaxies supports a progenitor channel with one or two degenerate objects has been disputed. While the predominant old population found in early-type galaxies supports longer delay times, the presence of recent star formation might indicate the opposite.
Download or read book Thermonuclear Supernovae written by P. Ruiz-Lapuente and published by Springer Science & Business Media. This book was released on 1997 with total page 920 pages. Available in PDF, EPUB and Kindle. Book excerpt: All theoretical and observational topics relevant to the understanding of the thermonuclear (Type Ia) supernova phenomenon are thoroughly and consistently reviewed by a panel including the foremost experts in the field. The book covers all aspects, ranging from the observations of SNe Ia at all stages and all wavelengths to the 2D and 3D modelling of thermonuclear flames in very dense plasmas. Scenarios for close binary evolution leading to SNe Ia are discussed. Particular emphasis is placed on the homogeneity vs. diversity of SNe Ia and on their use as standard candles to measure cosmological parameters. The book reflects the recent and very significant progress made in both the modelling of the explosions and in the observational field.
Download or read book Type Ia Supernovae written by Jens C. Niemeyer and published by Cambridge University Press. This book was released on 2000-05 with total page 150 pages. Available in PDF, EPUB and Kindle. Book excerpt: A unique and wide-ranging review of one of the most dramatic research results in astronomy in recent decades.
Download or read book Handbook of Supernovae written by Athem W. Alsabti and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Search for Supernova Type Ia Progenitors in the Magellanic Clouds written by Kelly Lepo and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Chemical Evolution of Galaxies written by Francesca Matteucci and published by Springer Science & Business Media. This book was released on 2012-01-05 with total page 237 pages. Available in PDF, EPUB and Kindle. Book excerpt: The term “chemical evolution of galaxies” refers to the evolution of abundances of chemical species in galaxies, which is due to nuclear processes occurring in stars and to gas flows into and out of galaxies. This book deals with the chemical evolution of galaxies of all morphological types (ellipticals, spirals and irregulars) and stresses the importance of the star formation histories in determining the properties of stellar populations in different galaxies. The topic is approached in a didactical and logical manner via galaxy evolution models which are compared with observational results obtained in the last two decades: The reader is given an introduction to the concept of chemical abundances and learns about the main stellar populations in our Galaxy as well as about the classification of galaxy types and their main observables. In the core of the book, the construction and solution of chemical evolution models are discussed in detail, followed by descriptions and interpretations of observations of the chemical evolution of the Milky Way, spheroidal galaxies, irregular galaxies and of cosmic chemical evolution. The aim of this book is to provide an introduction to students as well as to amend our present ideas in research; the book also summarizes the efforts made by authors in the past several years in order to further future research in the field.
Download or read book Progenitors of Type Ia Supernovae written by Cody Raskin and published by . This book was released on 2011 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Type Ia supernovae are important, but mysterious cosmological tools. Their standard brightnesses have enabled cosmologists to measure extreme distances and to discover dark energy. However, the nature of their progenitor mechanisms remains elusive, with many competing models offering only partial clues to their origins. Here, type Ia supernova delay times are explored using analytical models. Combined with a new observation technique, this model places new constraints on the characteristic time delay between the formation of stars and the first type Ia supernovae. This derived delay time (500 million years) implies low-mass companions for single degenerate progenitor scenarios. In the latter portions of this dissertation, two progenitor mechanisms are simulated in detail; white dwarf collisions and mergers. From the first of these simulations, it is evident that white dwarf collisions offer a viable and unique pathway to producing type Ia supernovae. Many of the combinations of masses simulated produce sufficient quantities of 56Ni (up to 0.51 solar masses) to masquerade as normal type Ia supernovae. Other combinations of masses produce 56Ni yields that span the entire range of supernova brightnesses, from the very dim and underluminous, with 0.14 solar masses, to the over-bright and superluminous, with up to 1.71 solar masses. The 56Ni yield in the collision simulations depends non-linearly on total system mass, mass ratio, and impact parameter. Using the same numerical tools as in the collisions examination, white dwarf mergers are studied in detail. Nearly all of the simulations produce merger remnants consisting of a cold, degenerate core surrounded by a hot accretion disk. The properties of these disks have strong implications for various viscosity treatments that have attempted to pin down the accretion times. Some mass combinations produce super-Chandrasekhar cores on shorter time scales than viscosity driven accretion. A handful of simulations also exhibit helium detonations on the surface of the primary that bear a resemblance to helium novae. Finally, some of the preliminary groundwork that has been laid for constructing a new numerical tool is discussed. This new tool advances the merger simulations further than any research group has done before, and has the potential to answer some of the lingering questions that the merger study has uncovered. The results of thermal diffusion tests using this tool have a remarkable correspondence to analytical predictions.
Download or read book Type Ia Supernovae written by Brandon Patel and published by . This book was released on 2015 with total page 130 pages. Available in PDF, EPUB and Kindle. Book excerpt: Type Ia supernovae (SNe Ia) are important cosmological probes, but we are uncertain how they explode. There are two progenitor channels for SNe~Ia: single and double degenerate white dwarf (WD) systems. In either model, we expect the system to be detectable as a Supersoft X-ray Source (SSS) for a significant amount of time before the explosion. By studying these SSSs, we hope to improve our understanding of SNe~Ia. In Chapter 2, we analyze an interesting source (r1-25) in M31. We found that the source exhibited spectral changes to harder X-ray states. r1-25 is the first source of its kind, and we require unique physical models to fit its behavior. We find that existing WD models are inconsistent with the spectra of the source. We explore new black hole and neutron star models, and find that they can model the unusual behavior of r1-25. In Chapter 3, we study three gravitationally lensed SNe from the Cluster Lensing And Supernova survey with Hubble (CLASH). Based on photometric classification, we found that two SNe (SN CLO12Car and CLN12Did) are likely to be SNe~Ia, while the classification of the third is inconclusive. Using multi-color light-curve fits to determine a standardized SN~Ia luminosity distance, we infer that SN CLO12Car was $sim 1.0 pm 0.2$ mag brighter than field SNe~Ia at a similar redshift and ascribe this to gravitational lens magnification. Similarly, SN CLN12Did is $sim 0.2 pm 0.2$ mag brighter than field SNe~Ia. From independent CLASH strong+weak lensing maps of the clusters, we derived similar magnifications for the two SNe~Ia. The two SNe~Ia provide a new test of the cluster lens model predictions: we find that the magnifications based on the SN~Ia brightness and those predicted by the lens maps are consistent. Finally, in Chapter ef{c4} we discuss a new light curve fitter for SNe~Ia, which we call Multicolor Light Curve Shapes 3 (MLCS3). The project has not been completed, but we discuss some of the features, and the expected improvements from MLCS3 in the chapter. With nearly 1000 SNe~Ia usable for cosmology, we are currently systematics, not statistics, limited for constraining cosmology. MLCS3 will provide more accurate distance measurements for the SNe~Ia using a variety of improvements that have been suggested in the literature.
Download or read book Supernova Explosions written by David Branch and published by Springer. This book was released on 2017-08-02 with total page 719 pages. Available in PDF, EPUB and Kindle. Book excerpt: Targeting advanced students of astronomy and physics, as well as astronomers and physicists contemplating research on supernovae or related fields, David Branch and J. Craig Wheeler offer a modern account of the nature, causes and consequences of supernovae, as well as of issues that remain to be resolved. Owing especially to (1) the appearance of supernova 1987A in the nearby Large Magellanic Cloud, (2) the spectacularly successful use of supernovae as distance indicators for cosmology, (3) the association of some supernovae with the enigmatic cosmic gamma-ray bursts, and (4) the discovery of a class of superluminous supernovae, the pace of supernova research has been increasing sharply. This monograph serves as a broad survey of modern supernova research and a guide to the current literature. The book’s emphasis is on the explosive phases of supernovae. Part 1 is devoted to a survey of the kinds of observations that inform us about supernovae, some basic interpretations of such data, and an overview of the evolution of stars that brings them to an explosive endpoint. Part 2 goes into more detail on core-collapse and superluminous events: which kinds of stars produce them, and how do they do it? Part 3 is concerned with the stellar progenitors and explosion mechanisms of thermonuclear (Type Ia) supernovae. Part 4 is about consequences of supernovae and some applications to astrophysics and cosmology. References are provided in sufficient number to help the reader enter the literature.
Download or read book Nature Versus Nurture written by Melissa Lynn Graham and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Supernovae of Type Ia, SNe Ia, are currently the most powerful tool of modern cosmology, but their progenitor scenario is not yet well constrained. Recent studies of SN Ia rates in radio-loud early-type galaxies, and members of rich clusters, suggest a possible influence on SN Ia explosions outside of the established correlation with the age of the parent galaxy's stellar population (via the current specific star formation rate, sSFR). These rates were used to show that the characteristics of SN Ia progenitor systems may be inconsistent with theoretical expectations of the most popular scenarios. The astrophysical question of this thesis is: do parent galaxy and environment influence the rates and properties of Type Ia supernovae, and, if so, how?Towards this end, we combine the database of Type Ia supernovae from the Canada-France-Hawaii Telescope's Supernova Legacy Survey with publicly available catalogs including: galaxy photometric and spectroscopic redshifts, radio and infrared sources, and members of galaxy groups and clusters. This is the most comprehensive set of multi-wavelength host properties and environment parameters for intermediate redshift Type Ia supernovae yet compiled. We present the SNLS SN Ia rate per unit mass in a variety of parent galaxy and environment samples. We also statistically assess the probability of discrepancies between our rates, those of previous works at low redshift, rates in the general population of galaxies, and predictions of established empirical SN Ia rate models. In general, we do not find statistically significant evidence for SN Ia rate enhancements over the general population in galaxies which are radio-loud, infrared-bright, or associated with galaxy groups and clusters. In cases where we do find a suggestive rate enhancement, it is always with less than 2-sigma confidence. These rates agree with established empirical rate models, which in turn are consistent with theoretical expectations of the most plausible progenitor scenarios. Furthermore, we find the properties of SNLS SNe Ia in these types of hosts and environments are consistent with the predictions of these scenarios. We conclude that, aside from the established correlation with host sSFR, no conclusive evidence is observed with SNLS data for strictly environmental effects on SN Ia rates. This supports their continued status as cosmological standard candles.
Download or read book Luminous Supersoft X Ray Sources As Progenitors of Type Ia Supernovae written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-12-29 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: In some luminous supersoft X-ray sources, hydrogen accretes onto the surface of a white dwarf at rates more-or-less compatible with steady nuclear burning. The white dwarfs in these systems therefore have a good chance to grow in mass. Here we review what is known about the rate of Type la supernovae that may be associated with SSSS. Observable consequences of the conjecture that SSSs can be progenitors of Type Ia supernovae are also discussed. DiStefano, R. Goddard Space Flight Center NASA-CR-203600, NAS 1.26:203600 NAG5-3022; GER-9450087...
Download or read book Supernova Rates Rise Times and Their Relations to Progenitors written by Santiago Gonzalez Gaitan and published by . This book was released on 2011 with total page 312 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supernovae are fundamental in astronomy: they inject high mass elements into the interstellar medium enriching the chemistry of galaxies, they feed processes of star formation and active galactic nuclei, and they have been a key for the developments in cosmology of the past decades.This dissertation presents a set of subluminous type Ia supernovae (SNe Ia) at z > 0.1 from the Supernova Legacy Survey (SNLS). These faint and short-lived transients are found in massive and passive host galaxies. We measure a volumetric rate as a function of redshift that is different from the normal SN Ia population. The observations point towards a long delay time since the birth of the progenitors systems and argue for progenitor stars of initial low mass.We calculate a stretch-corrected rise-time since explosion to maximum brightness for different sets of SNe Ia. We find that a fiducial 17 day quadratic rise is sufficient to explain all SNe Ia, including subluminous ones, arguing for their homogeneity throughout the entire light-curve. Subluminous SNe Ia are powered by as little as 0.05 solar masses of radioactive nickel synthesized in the explosion. Theoretical models need to explain these challenging weak explosions within the framework of SNe Ia.Finally, we develop one of the first robust automated techniques to identify plateau supernovae (SNe IIP) in large photometric transient surveys. This simple method was tested with a variety of real and simulated SN samples and proved to be effective across different redshifts. Such a photometric typing will be of great power for coming surveys and will allow numerous scientific studies of SNe IIP.
Download or read book Observational Constraints on the Progenitors of Type Ia Supernovae written by Georgios Dimitriadis and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Type Ia supernovae written by Dale Andrew Howell and published by . This book was released on 2000 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Supernova Rates Rise Ttmes and Their Relations to Progenitors written by Santiago Gonzalez Gaitan and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
