THE ORIGIN OF COLOR GRADIENTS IN EARLY-TYPE SYSTEMS AND THEIR COMPACTNESS AT HIGH-z
Journal Article
·
· Astrophysical Journal (Online)
- INAF-Osservatorio Astronomico di Capodimonte, Napoli (Italy)
- Instituto Nacional de Pesquisas Espaciais-INPE/MCT, Sao Paulo (Brazil)
In this Letter, we present mean optical+NIR color gradient estimates for 5080 early-type galaxies (ETGs) in the grizY JHK wavebands of the Sloan Digital Sky Survey plus the UKIRT Infrared Deep Sky Survey. The color gradient is estimated as the logarithmic slope of the radial color profile in ETGs. With such a large sample size, we study the variation of the mean color gradient as a function of waveband with unprecedented accuracy. We find that (1) color gradients are mainly due, on average, to a metallicity variation of about -0.4 dex per decade in galaxy radius; and (2) a small, but significant, positive age gradient is present, on average, in ETGs, with the inner stellar population being slightly younger, by {approx}0.1 dex per radial decade, than the outer one. Also, we show that the presence of a positive mean age gradient in ETGs, as found in the present study, implies their effective radius to be smaller at high-z, consistent with observations.
- OSTI ID:
- 21313044
- Journal Information:
- Astrophysical Journal (Online), Journal Name: Astrophysical Journal (Online) Journal Issue: 2 Vol. 699; ISSN 1538-4357
- Country of Publication:
- United States
- Language:
- English
Similar Records
ON THE RADIAL STELLAR CONTENT OF EARLY-TYPE GALAXIES AS A FUNCTION OF MASS AND ENVIRONMENT
OPTICAL-NEAR-INFRARED COLOR GRADIENTS AND MERGING HISTORY OF ELLIPTICAL GALAXIES
SPIDER. IV. OPTICAL AND NEAR-INFRARED COLOR GRADIENTS IN EARLY-TYPE GALAXIES: NEW INSIGHT INTO CORRELATIONS WITH GALAXY PROPERTIES
Journal Article
·
Thu Oct 20 00:00:00 EDT 2011
· Astrophysical Journal Letters
·
OSTI ID:21565369
OPTICAL-NEAR-INFRARED COLOR GRADIENTS AND MERGING HISTORY OF ELLIPTICAL GALAXIES
Journal Article
·
Mon Apr 01 00:00:00 EDT 2013
· Astrophysical Journal
·
OSTI ID:22167502
SPIDER. IV. OPTICAL AND NEAR-INFRARED COLOR GRADIENTS IN EARLY-TYPE GALAXIES: NEW INSIGHT INTO CORRELATIONS WITH GALAXY PROPERTIES
Journal Article
·
Sun Nov 14 23:00:00 EST 2010
· Astronomical Journal (New York, N.Y. Online)
·
OSTI ID:21443187