Browsing by Subject "ii-p supernovae"
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Item Type Ia Supernova Rate Measurements To Redshift 2.5 From CANDELS: Searching For Prompt Explosions In The Early Universe(2014-07) Rodney, Steven A.; Riess, Adam G.; Strolger, Louis-Gregory; Dahlen, Tomas; Graur, Or; Casertano, Stefano; Dickinson, Mark E.; Ferguson, Henry C.; Garnavich, Peter; Hayden, Brian; Jha, Saurabh W.; Jones, David O.; Kirshner, Robert P.; Koekemoer, Anton M.; McCully, Curtis; Mobasher, Bahram; Patel, Brandon; Weiner, Benjamin J.; Cenko, S. Bradley; Clubb, Kelsey I.; Cooper, Michael; Filippenko, Alexei V.; Frederiksen, Teddy F.; Hjorth, Jens; Leibundgut, Bruno; Matheson, Thomas; Nayyeri, Hooshang; Penner, Kyle; Trump, Jonathan; Silverman, Jeffrey M.; U, Vivian; Bostroem, K. Azalee; Rajan, Abhijith; Wolff, Schuyler; Faber, S. M.; Grogin, Norman A.; Kocevski, Dale; Challis, Peter; Silverman, Jeffrey M.dThe Cosmic Assembly Near-infrared Deep Extragalactic Legacy Survey (CANDELS) was a multi-cycle treasury program on the Hubble Space Telescope (HST) that surveyed a total area of -0.25 deg2 with -900 HST orbits spread across five fields over three years. Within these survey images we discovered 65 supernovae (SNe) of all types, out to z 2.5. We classify -24 of these as Type Ia SNe (SNe Ia) based on host galaxy redshifts and SN photometry (supplemented by grism spectroscopy of six SNe). Here we present a measurement of the volumetric SN Ia rate as a function of redshift, reaching for the first time beyond z =- 2 and putting new constraints on SN Ia progenitor models. Our highest redshift bin includes detections of SNe that exploded when the universe was only -3 Gyr old and near the peak of the cosmic star formation history. This gives the CANDELS high redshift sample unique leverage for evaluating the fraction of SNe Ia that explode promptly after formation (<500 Myr). Combining the CANDELS rates with all available SN Ia rate measurements in the literature we find that this prompt SN Ia fraction is fp = 0.53st=sg.Zc6', consistent with a delay time distribution that follows a simple t-1 power law for all times t > 40 Myr. However, mild tension is apparent between ground-based low-z surveys and space-based high-z surveys. In both CANDELS and the sister HST program CLASH (Cluster Lensing And Supernova Survey with Hubble), we find a low rate of SNe Ia at z > 1. This could be a hint that prompt progenitors are in fact relatively rare, accounting for only 20% of all SN Ia explosions-though further analysis and larger samples will be needed to examine that suggestion. Key words: infrared: general - supernovae:Item The Young, Massive, Star Cluster Sandage-96 After The Explosion Of Supernova 2004dj In NGC 2403(2009-04) Vinko, Jozsef; Sarneczky, K.; Balog, Z.; Immler, S.; Sugerman, B. E. K.; Brown, Peter J.; Misselt, K.; Szabo, G. M.; Csizmadia, S.; Kun, M.; Klagyivik, P.; Foley, Ryan J.; Filippenko, Alexei V.; Csak, B.; Kiss, L. L.; Vinko, JozsefThe bright Type II-plateau supernova (SN) 2004dj occurred within the young, massive stellar cluster Sandage-96 in a spiral arm of NGC 2403. New multiwavelength observations obtained with several ground-based and space-based telescopes were combined to study the radiation from Sandage-96 after SN 2004dj faded away. Sandage-96 started to dominate the flux in the optical bands starting from 2006 September (similar to 800 days after explosion). The optical fluxes are equal to the pre-explosion ones within the observational uncertainties. An optical Keck spectrum obtained similar to 900 days after explosion shows the dominant blue continuum from the cluster stars shortward of 6000 angstrom as well as strong SN nebular emission lines redward. The integrated spectral energy distribution (SED) of the cluster has been extended into the ultraviolet region by archival XMM-Newton and new Swift observations, and compared with theoretical models. The outer parts of the cluster have been resolved by the Hubble Space Telescope, allowing the construction of a color-magnitude diagram (CMD). The fitting of the cluster SED with theoretical isochrones results in cluster ages distributed between 10 and 40 Myr, depending on the assumed metallicity and the theoretical model family. The isochrone fitting of the CMDs indicates that the resolved part of the cluster consists of stars having a bimodal age distribution: a younger population at similar to 10-16 Myr and an older one at similar to 32-100 Myr. The older population has an age distribution similar to that of the other nearby field stars. This may be explained with the hypothesis that the outskirts of Sandage-96 are contaminated by stars captured from the field during cluster formation. The young age of Sandage-96 and the comparison of its pre and postexplosion SEDs suggest 12 less than or similar to M(prog) less than or similar to 20 M(circle dot) as the most probable mass range for the progenitor of SN 2004dj. This is consistent with, but perhaps slightly higher than, most of the other Type II-plateau SN progenitor masses determined so far.