J/A+A/620/A202 MAMMOTH-1 450 and 850um images (Arrigoni Battaia+, 2018)
Overdensity of submillimeter galaxies around the z~=2.3 MAMMOTH-1 nebula.
The environment and powering of an enormous Lyman-alpha nebula.
Arrigoni Battaia F., Chen C.-C., Fumagalli M., Cai Z. , Calistro Rivera G.,
Xu J., Smail I., Prochaska J.X., Yang Y., De Breuck C.
<Astron. Astrophys. 620, A202 (2018)>
=2018A&A...620A.202A 2018A&A...620A.202A (SIMBAD/NED BibCode)
ADC_Keywords: Nebulae ; Clusters, galaxy ; Photometry, millimetric/submm
Keywords: submillimeter: galaxies - galaxies: high-redshift - galaxies: halos -
galaxies: clusters: general - galaxies: evolution -
large-scale structure of Universe
Abstract:
In the hierarchical model of structure formation, giant elliptical
galaxies form through merging processes within the highest density
peaks known as protoclusters. While high-redshift radio galaxies
usually pinpoint the location of these environments, we have recently
discovered at z∼2-3 three enormous (>200kpc) Lyman-alpha nebulae
(ELANe) that host multiple active galactic nuclei (AGN) and that are
surrounded by overdensities of Lyman- emitters (LAE). These regions
are prime candidates for massive protoclusters in the early stages of
assembly. To characterize the star-forming activity within these rare
structures - both on ELAN and protocluster scales - we have initiated
an observational campaign with the James Clerk Maxwell Telescope
(JCMT) and the Atacama Pathfinder EXperiment (APEX) telescopes. In
this paper we report on sensitive SCUBA-2/JCMT 850 and 450um
observations of a 128 arcmin2 field comprising the ELAN MAMMOTH-1,
together with the peak of the hosting BOSS1441 LAE overdensity at
z=2.32. These observations unveil 4.0±1.3 times higher source counts
at 850um with respect to blank fields, likely confirming the presence
of an overdensity also in obscured tracers. We find a strong detection
at 850um associated with the continuum source embedded within the ELAN
MAMMOTH-1, which - together with the available data from the
literature - allow us to constrain the spectral energy distribution of
this source to be of an ultra-luminous infrared galaxy (ULIRG) with a
far-infrared luminosity of LSFFIR=2.4+7.4+-2.1x1012L☉,
and hosting an obscured AGN. Such a source is thus able to power a
hard photoionization plus outflow scenario to explain the extended
Lyman-, HeII1640; and CIV1549 emission, and their kinematics. In
addition, the two brightest detections at 850um (f850>18mJy) sit at
the density peak of the LAEs; overdensity, likely pinpointing the
core of the protocluster. Future multiwavelength and spectroscopic
datasets targeting the full extent of the BOSS1441 overdensity have
the potential to firmly characterize a cosmic nursery of giant
elliptical galaxies, and ultimately of a massive cluster.
Description:
The SCUBA-2 observations for the MAMMOTH-1 field were conducted at
JCMT during flexible observing in 2018 January 16, 17, and 18 (program
ID: M17BP024) under good weather conditions (band 1 and 2,
τ225GHz≤0.07). The observations were performed with a Daisy
pattern covering ~=13.7' in diameter, and were centered at the
location of the ELAN MAMMOTH-1 as indicated in Cai et al.
(2017ApJ...837...71C 2017ApJ...837...71C). We note, however, that the exact coordinate of
the ELAN MAMMOTH-1 have been refined to be RA=14:41:24.456, and
DE=+40:03:09.45. To facilitate the scheduling we divided the
observations into six scans/cycles of about 30 minutes, for a total of
three hours.
Objects:
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RA (2000) DE Designation(s)
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14 41 24.456 +40 03 09.45 MAMMOTH-1 = Name MAMMOTH-1
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 130 2 List of fits images
fits/* . 2 Individual fits images
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 9 F9.5 deg RAdeg Right Ascension of center (J2000)
10- 18 F9.5 deg DEdeg Declination of center (J2000)
20- 22 I3 --- Nx Number of pixels along X-axis
24- 26 I3 --- Ny Number of pixels along Y-axis
28- 50 A23 "datime" Obs.date Observation date (YYYY-MM-DDThh:mm:ss.sss)
52- 54 I3 um lambda [450/850] Observed wavelength
56- 59 I4 Kibyte size Size of FITS file
61- 84 A24 --- FileName Name of FITS file, in subdirectory fits
86-130 A45 --- Title Title of the FITS file
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Acknowledgements:
Fabrizio Arrigoni Battaia, farrigon(at)eso.org
(End) Patricia Vannier [CDS] 03-Dec-2018