Mapping the spatial distribution of star formation in cluster galaxies at z ~0.5 with the Grism Lens-Amplified Survey from Space (GLASS)
Date Issued
2016
Author(s)
•
Treu, T.
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Schmidt, K. B.
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Dressler, A.
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•
Bradač, M.
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Brammer, G. B.
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Hoag, A.
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Huang, K.
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Malkan, M.
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Trenti, M.
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von der Linden, A.
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Abramson, L.
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He, J.
•
Morris, G.
Abstract
What physical processes regulate star formation in dense environments? Understanding why galaxy evolution is environment dependent is one of the key questions of current astrophysics. I will present the first characterization of the spatial distribution of star formation in cluster galaxies at z~0.5, and compare to a field control sample, in order to quantify the role of different physical processes that are believed to be responsible for shutting down star formation (Vulcani et al. 2015, Vulcani et al. in prep). The analysis makes use of data from the Grism Lens-Amplified Survey from Space (GLASS), a large HST cycle-21 program targeting 10 massive galaxy clusters with extensive HST imaging from CLASH and the Frontier Field Initiative. The program consists of 140 primary and 140 parallel orbits of near-infrared WCF3 and optical ACS slitless grism observations, which result in 3D spectroscopy of hundreds of galaxies. The grism data are used to produce spatially resolved maps of the star formation density, while the stellar mass density and optical surface brightness are obtained from multiband imaging. I will describe quantitative measures of the spatial location and extent of the star formation rate. I will show that both in clusters and in the field, Hα is more extended than the rest-frame UV continuum in 60% of the cases, consistent with diffuse star formation and inside out growth. The Hα emission appears more extended in cluster galaxies than in the field, pointing perhaps to ionized gas being stripped and/or star formation being enhanced at large radii. The peak of the Hα emission and that of the continuum are offset by less than 1 kpc. I will also correlate the properties of the Hα maps to the cluster global properties, such as the hot gas density, and the surface mass density. The characterization of the spatial distribution of Halpha provides a new window, yet poorly exploited, on the mechanisms that regulate star formation and morphological transformation in dense environments.
Coverage
The Interplay between Local and Global Processes in Galaxies,
Start page
29
Conferenece
The Interplay between Local and Global Processes in Galaxies,
Conferenece place
Cozumel, Mexico
Conferenece date
11-15 April, 2016
Ads BibCode
2016ilgp.confE..29V
Rights
open.access
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Name
Vulcani_Cozumel2016.pdf
Description
Talk
Size
4.71 MB
Format
Adobe PDF
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