J/AJ/167/49 Ha equivalent with estimated for galaxy clusters (Wittman+, 2024)
Distribution of Ha Emitters in Merging Galaxy Clusters
Wittman D., Imani D., Olden R.H., Golovich N.
<Astron. J., 167, 49 (2024)>
=2024AJ....167...49W 2024AJ....167...49W
ADC_Keywords: Clusters, open; Star Forming Region; Photometry, H-alpha
Keywords: Galaxy clusters ; Star formation
Abstract:
Studies of star formation in various galaxy cluster mergers have
reached apparently contradictory conclusions regarding whether mergers
stimulate star formation, quench it, or have no effect. Because the
mergers studied span a range of time since pericenter (TSP), it is
possible that the apparent effect on star formation is a function of
the TSP. We use a sample of 12 bimodal mergers to assess the star
formation as a function of TSP. We measure the equivalent width of the
Hα emission line in ∼100 member galaxies in each merger,
classify galaxies as emitters or nonemitters, and then classify
emitters as star-forming galaxies (SFGs) or active galactic nucleus
(AGN) based on the [NII] λ6583 line. We quantify the
distribution of SFG and AGN relative to nonemitters along the spatial
axis defined by the subcluster separation. The SFG and AGN fractions
vary from merger to merger but show no trend with TSP. The spatial
distribution of SFG is consistent with that of nonemitters in eight
mergers, but show significant avoidance of the system center in the
remaining four mergers, including the three with the lowest TSP. If
there is a connection between star formation activity and TSP, probing
it further will require more precise TSP estimates and more mergers
with TSP in the range of 0-400Myr.
Description:
We measure the equivalent width of the Hα emission line in ∼100
member galaxies.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 30 1414 Halpha equivalent width estimates
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See also:
J/ApJ/559/606 : Star formation in spectroscopic survey (Carter+, 2001)
J/AJ/125/2427 : 1.4GHz flux densities of Abell 2255 galaxies (Miller+, 2003)
J/ApJ/772/131 : Musket Ball Cluster redshift catalog (Dawson, 2013)
J/MNRAS/450/630 : MC2; SFR in CIZA J2242.8+5301 (Sobral+, 2015)
J/ApJS/240/39 : Merging galaxy cluster deep observations (Golovich+, 2019)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 8 F8.4 deg RAdeg [2/341] Right ascension in decimal degrees (J2000)
10- 17 F8.4 deg DEdeg [-29/67] Declination in decimal degrees (J2000)
19- 25 F7.2 0.1nm EW [-159/4.61] Equivalent width in angstroms
27- 30 F4.2 0.1nm e_EW [0.03/7] Uncertainty in EW
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History:
From electronic version of the journal
(End) Prepared by [AAS], Coralie Fix [CDS], 03-Jun-2024