J/MNRAS/447/1126 Halpha measurements in Abell 2465 (Wegner+, 2015)
The double galaxy cluster Abell 2465. II. Star formation in the cluster.
Wegner G.A., Chu D.S., Hwang H.S.
<Mon. Not. R. Astron. Soc., 447, 1126-1140 (2015)>
=2015MNRAS.447.1126W 2015MNRAS.447.1126W (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Photometry, H-alpha
Keywords: galaxies: clusters: general -
galaxies: clusters: individual: Abell 2465 - galaxies: evolution -
galaxies: starburst
Abstract:
We investigate the star formation rate and its location in the major
merger cluster Abell 2465 at z=0.245. Optical properties of the
cluster are described in. Measurements of the Hα and infrared
dust emission of galaxies in the cluster were made with an
interference filter centred on the redshifted line at a wavelength of
817 nm and utilized data from the Wide-field Infrared Survey Explorer
satellite 12µm band. Imaging in the Johnson U and B bands was
obtained, and along with Sloan Digital Sky Survey u and r was used to
study the blue fraction, which appears enhanced, as a further
signature of star formation in the cluster. Star formation rates were
calculated using standard calibrations. The total star formation rate
normalized by the cluster mass, ΣSFR/Mcl compared to
compilations for other clusters indicate that the components of Abell
2465 lie above the mean z and Mcl relations, suggestive that
interacting galaxy clusters have enhanced star formation. The
projected radial distribution of the star-forming galaxies does not
follow an NFW profile and is relatively flat indicating that fewer
star-forming galaxies are in the cluster centre. The morphologies of
the Hα sources within R200 for the cluster as a whole indicate
that many are disturbed or merging, suggesting that a combination of
merging or harassment is working.
Description:
The wavelength of the Hα line at the redshift of Abell 2465 is
near 817nm in a clear spectral region between the many telluric
emission lines. A custom narrow-band filter for observing Hα was
obtained from the Andover Corp. It has a peak transmission at 817.7nm
(m817) and a full width at half-maximum (FWHM) of 8.77nm. The wide
filter was a Gunn i (ig) filter with nearly the same central
wavelength of 820nm and a FWHM of 185nm, and was manufactured by
Custom Scientific.
Hα observations of Abell 2465 were obtained 2012 September 19-23
using the 2.4m Hiltner telescope at the MDM Observatory on Kitt Peak.
The 'Nellie' CCD was used.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 72 2180 The observed photometric quantities measured
in Abell 2465
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right ascension (J2000)
11- 19 F9.6 deg DEdeg Declination (J2000)
20- 25 F6.3 mag imag Gunn i magnitude
27- 31 F5.3 mag e_imag rms uncertainty on imag
33- 38 F6.3 mag m817 817nm filter magnitude
40- 44 F5.3 mag e_m817 rms uncertainty on m817
46- 50 F5.1 0.1nm EWHa Hα equivalent width (1)
52- 57 F6.1 0.1nm e_EWHa rms uncertainty on EWHa
59- 65 F7.2 10-19W/m2/arcmin2 FHa Hα flux (2)
67- 72 F6.2 10-19W/m2/arcmin2 e_FHa rms uncertainty on FHa (2)
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Note (1): positive values denote emission and negative absorption.
Note (2): Hα fluxes in 10-16erg/s/cm2/arcmin2.
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History:
From electronic version of the journal
References:
Wegner et al., Paper I 2011MNRAS.413.1333W 2011MNRAS.413.1333W
(End) Patricia Vannier [CDS] 01-Jul-2015