We present extensive optical and infrared photometry of the afterglow of gamma-ray burst (GRB) 030329 and its associated supernova (SN) 2003dh over the first two months after detection (2003 March 30-May 29 UT). Optical spectroscopy from a variety of telescopes is shown and, when combined with the photometry, allows an unambiguous separation between the afterglow and supernova contributions. The optical afterglow of the GRB is initially a power-law continuum but shows significant color variations during the first week that are unrelated to the presence of a supernova. The early afterglow light curve also shows deviations from the typical power-law decay. A supernova spectrum is first detectable ∼ 7 days after the burst and dominates the light after ∼ 11 days. The spectral evolution and the light curve are shown to closely resemble those of SN 1998bw, a peculiar Type Ic SN associated with GRB 980425, and the time of the supernova explosion is close to the observed time of the GRB. It is now clear that at least some GRBs arise from core-collapse SNe.
We present the fundamental plane (FP) for 38 early-type galaxies in the two rich galaxy clusters RX J0152.7Ϫ1357 ( ) and RX J1226.9ϩ3332 ( ), reaching a limiting magnitude of in z p 0.83 z p 0.89 M p Ϫ19.8B the rest frame of the clusters. While the zero-point offset of the FP for these high-redshift clusters relative to our low-redshift sample is consistent with passive evolution with a formation redshift of , the FP for z ≈ 3.2 form the high-redshift clusters is not only shifted as expected for a mass-independent but rotated relative to the z form low-redshift sample. Expressed as a relation between the galaxy masses and the mass-to-light ratios, the FP is significantly steeper for the high-redshift clusters than for our low-redshift sample. We interpret this as a mass dependency of the star formation history, as has been suggested by other recent studies. The low-mass galaxies ( ) have experienced star formation as recently as (1.5 Gyr prior to their look-back time), while 10.3 10 M z ≈ 1.35, galaxies with masses larger than had their last major star formation episode at .11.310 M z 1 4.5 , Subject headings: galaxies: clusters: individual (RX J0152.7Ϫ1357, RX J1226.9ϩ3332) -galaxies: evolution -galaxies: stellar contentThe fundamental plane (FP) for elliptical (E) and lenticular (S0) galaxies is a key scaling relation, which relates the effective radii, the mean surface brightnesses, and the velocity dispersions in a relation that is linear in logarithmic space (e.g., Dressler et al. 1987;Djorgovski & Davis 1987;Jørgensen et al. 1996. The FP can be interpreted as a relation between the galaxy masses and their mass-to-light ratios ( ). For low-redshift cluster galaxies, the FP has very M/L low internal scatter (e.g., JFK1996). It is therefore a powerful tool for studying the evolution of the as a function of M/L redshift (e.g., Jørgensen et al. 1999;Kelson et al. 2000;van de Ven et al. 2003;Gebhardt et al. 2003;Wuyts et al. 2004;Treu et al. 2005;Ziegler et al. 2005). These authors all find that the FP at is consistent with the passive evoz p 0.2-1.0 lution of the stellar populations of the galaxies, generally with a formation redshift . Most previous studies of the FP z 1 2 form at cover fairly small samples of galaxies in each z p 0.2-1.0 cluster and are limited to a narrow range in luminosities, and therefore masses, making it very difficult to detect possible differences in the FP slope. A few recent studies indicated a steepening of the FP slope for galaxies (di Serego Ali- little for the two choices of profiles. In the following we use the parameters from -fits for consistency with our low-red-1/4 r shift comparison data. None of the main conclusions of this Letter would change had we chosen to use the Sérsic fits. Masses of the galaxies are derived as .Our Coma Cluster sample serves as the low-redshift reference sample (Jørgensen 1999). We have obtained new B-band photometry of this sample with the McDonald Observatory 0.8 m telescope and the Primary Focus Camera (Claver 1995). The data were r...
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.