J/MNRAS/481/5630 MAHALO Deep Cluster Survey II (Shimakawa+, 2018)
MAHALO Deep Cluster Survey II. Characterizing massive forming galaxies in the
Spiderweb protocluster at z = 2.2.
Shimakawa R., Koyama Y., Rottgering H.J.A., Kodama T., Hayashi M.,
Hatch N.A., Dannerbauer H., Tanaka I., Tadaki K.-I., Suzuki T.L.,
Fukagawa N., Cai Z., Kurk J.D.
<Mon. Not. R. Astron. Soc., 481, 5630-5650 (2018)>
=2018MNRAS.481.5630S 2018MNRAS.481.5630S (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies ; Redshifts
Keywords: galaxies: clusters: individual: PKS 1138-262 -
galaxies: evolution - galaxies: formation - galaxies: high-redshift
Abstract:
This paper is the second in a series presenting the results of our
deep Hα-line survey towards protoclusters at z>2, based on
narrow-band imaging with the Subaru Telescope. This work investigates
massive galaxies in a protocluster region associated with a radio
galaxy (PKS 1138-262), the Spiderweb galaxy, at z=2.2. Our 0.5 mag
deeper narrow-band imaging than previous surveys collects a total of
68 Hα emitters (HAE). Here, 17 out of the 68 are newly
discovered protocluster members. First, a very high characteristic
stellar mass of M*=1011.73M☉ is measured from a Schechter
function fit to the mass distribution of HAEs. Together with the
Chandra X-ray data, we find that four out of six massive HAEs
(M*>1011M☉) show bright X-ray emission, suggesting that they
host active galactic nuclei (AGNs). Their mass estimates, therefore,
would be affected by the nuclear emission from AGNs. Notably, the
X-ray-detected HAEs are likely positioned near the boundary between
star-forming and quiescent populations in the rest-frame UVJ plane.
Moreover, our deep narrow-band data succeed in probing the bright
Hα (+[NII]) line nebula of the Spiderweb galaxy extending over
∼100 physical kpc. These results suggest that the massive galaxies in
the Spiderweb protocluster are on the way to becoming the bright red
sequence objects seen in local galaxy clusters, where AGNs might play
an essential role in their quenching processes, though a more
statistical database is needed to build a general picture.
Description:
We employ the multi broad-band and narrow-band data set from MDCS and
the literature. The data consist of B, F475W, F814W, z', Y, J, H, K_s,
MOIRCS_ (hereafter Ks), K_s, HAWKI_, and NB2071. The z', J, Ks, and
NB2071 images are based on the past MAHALO-Subaru campaign (S10B-028I,
Kodama et al.; Koyama et al. 2013MNRAS.428.1551K 2013MNRAS.428.1551K) and MDCS (S15A-047,
Kodama et al.). The reduced B-band image was recently obtained with
Suprime-Cam on the Subaru Telescope between May and June 2017. In
addition, we use the reduced Hubble Space Telescope (HST) ACS/WFC data
(F475W, F814W), obtained from the Hubble Legacy Archive (HLA), and
reduced near-infrared (NIR) images (Y, H, K_s, HAWKI_) taken with
HAWK-I on Very Large Telescope (VLT). We also introduce here NB2071
data, taken as part of the MDCS with the Multi-Object Infrared Camera
and Spectrograph (MOIRCS; Ichikawa et al. 2006SPIE.6269E..16I 2006SPIE.6269E..16I; Suzuki
et al. The narrow-band filter, NB2071 has a central wavelength of
2.071µm with the full width at half-maximum (FWHM) of 270Å,
which covers the Hα-redshift 2.15±0.02.
2008PASJ...60.1347S 2008PASJ...60.1347S) on the Subaru Telescope. The observations were
executed between April 30 and May 6, 2015, under photometric
conditions with seeing FWHM ∼0.6arcsec.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablec1.dat 123 68 Emitter catalogue
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Byte-by-byte Description of file: tablec1.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- ID Identification number (1)
4- 12 F9.5 deg RAdeg Right ascension (J2000)
14- 22 F9.5 deg DEdeg Declination (J2000)
24- 31 F8.4 --- z ?=-99. Spectroscopic redshift
33- 35 A3 --- f_z Flag on z (2)
37- 41 F5.2 [Msun] Mstar Log stellar mass
43- 46 F4.2 [Msun] e_Mstar Lower 1σ error on Mstar
48- 51 F4.2 [Msun] E_Mstar Upper 1σ error on Mstar
53- 56 F4.2 mag Av Amount of dust extinction at V-band
58- 61 F4.2 mag e_Av Lower 1σ error on Av
63- 66 F4.2 mag E_Av Upper 1σ error on Av
68- 75 E8.4 10-7W LHa Observed Hα luminosity
77- 84 E8.4 10-7W e_LHa 1σ error on LHa
86- 90 F5.3 [Msun/yr] SFR Dust-corrected log SFRHα
92- 96 F5.3 [Msun/yr] e_SFR Lower 1σ error on SFR
98-102 F5.3 [Msun/yr] E_SFR Upper 1σ error on SFR
104-108 F5.3 mag U-V Rest-frame (U-V) colour
110-115 F6.3 mag V-J Rest-frame (V-J) colour
117-119 I3 --- Xflag ?=-99 X-ray counterpart (id in
Pentericci et al. 2002A&A...396..109P 2002A&A...396..109P),
[PKC2002] NN in Simbad
121-123 I3 --- LAE ?=-99 Ly α emitter counterpart
(id in Kurk et al. 2004A&A...428..793K 2004A&A...428..793K),
[KPR2004] LyA NNNN in Simbad
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Note (1): ID 73 in this work corresponds to the Spiderweb radio galaxy
Note (2): Flag as follows:
P02 = Pentericci et al. (2002A&A...396..109P 2002A&A...396..109P)
K04 = Kurk et al. (2004A&A...428..817K 2004A&A...428..817K)
C05 = Croft et al. (2005AJ....130..867C 2005AJ....130..867C)
D10 = Doherty et al. (2010A&A...509A..83D 2010A&A...509A..83D)
T13 = Tanaka et al. (2013ApJ...772..113T 2013ApJ...772..113T)
S14 = Shimakawa et al. (2014MNRAS.441L...1S 2014MNRAS.441L...1S)
* = For this object the value 79 given on the original catalogue
was omitted as it doesn't correspond to any of the listed references
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 15-Jun-2022