J/MNRAS/489/2792 Clumps and satellites impact on galaxy mass (Zanella+, 2019)
A contribution of star-forming clumps and accreting satellites to the mass
assembly of z∼2 galaxies.
Zanella A., Le Floc'h E., Harrison C.M., Daddi E., Bernhard E., Gobat R.,
Strazzullo V., Valentino F., Cibinel A., Sanchez Almeida J., Kohandel M.,
Fensch J., Behrendt M., Burkert A., Onodera M., Bournaud F., Scholtz J.
<Mon. Not. R. Astron. Soc., 489, 2792-2818 (2019)>
=2019MNRAS.489.2792Z 2019MNRAS.489.2792Z (SIMBAD/NED BibCode)
ADC_Keywords: Clusters, galaxy ; Galaxies, spectra ; Galaxies, photometry ;
Ultraviolet ; Optical ; Infrared
Keywords: galaxies: evolution - galaxies: interactions - galaxies: irregular -
galaxies: ISM - galaxies: star formation - galaxies: structure
Abstract:
We investigate the contribution of clumps and satellites to the galaxy
mass assembly. We analysed spatially resolved HubbleSpace Telescope
observations (imaging and slitless spectroscopy) of 53 star-forming
galaxies at z∼1-3. We created continuum and emission line maps and
pinpointed residual 'blobs' detected after subtracting the galaxy
disc. Those were separated into compact (unresolved) and extended
(resolved) components. Extended components have sizes ∼2kpc and
comparable stellar mass and age as the galaxy discs, whereas the
compact components are 1.5dex less massive and 0.4dex younger than the
discs. Furthermore, the extended blobs are typically found at larger
distances from the galaxy barycentre than the compact ones. Prompted
by these observations and by the comparison with simulations, we
suggest that compact blobs are in situ formed clumps, whereas the
extended ones are accreting satellites. Clumps and satellites enclose,
respectively, ∼20 per cent and ~<80 per cent of the galaxy stellar
mass, ∼30 per cent and ∼20 per cent of its star formation rate.
Considering the compact blobs, we statistically estimated that massive
clumps (M{*}≳109M☉) have lifetimes of ∼650Myr, and the less
massive ones (108< M{*}<109M☉) of ∼145Myr. This supports
simulations predicting long-lived clumps (lifetime ≳100Myr). Finally,
~<30 per cent (13 per cent) of our sample galaxies are undergoing
single (multiple) merger(s), they have a projected separation ~<10kpc,
and the typical mass ratio of our satellites is 1:5 (but ranges
between 1:10 and 1:1), in agreement with literature results for close
pair galaxies.
Description:
Spectroscopic and photometric observations targeting the distant
galaxy cluster Cl J1449+0856 (Gobat et al. 2013ApJ...776....9G 2013ApJ...776....9G) were
performed in Cycle 18 (PI: E. Daddi) with HST Wide Field Camera 3
(WFC3) using the G141 grism and F140W filter. The imaging was mainly
taken to provide information on source positions and morphologies, to
correctly model the spectra and facilitate the extraction. Additional
HST/WFC3 observations were taken with the F105W and F606W filters
during Cycle 21 (PI: V. Strazzullo). The data were reduced using the
aXe pipeline (Kummel et al. 2009PASP..121...59K 2009PASP..121...59K).
A Subaru/MOIRCS near-IR spectroscopic follow-up of 76 sources in the
cluster Cl J1449+0856 field has been performed in 2013 April. The data
have been reduced with the MCSMDP pipeline (Yoshikawa et al.
2010ApJ...718..112Y 2010ApJ...718..112Y) combined with custom IDL scripts (Valentino et
al. 2015ApJ...801..132V 2015ApJ...801..132V).
We started with a parent sample of 135 galaxies identified in the
F140W imaging and we only considered the 110 galaxies that were
showing at least one emission line ([OII], Hβ, [OIII], and/or
Hα) in the 1D spectra. Our final sample, after the
cross-correlation procedure and the exclusion of one X-ray detected
AGN, is made of 53 galaxies and among them 9 are confirmed members of
the Cl J1449+0856 cluster.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tabled1.dat 162 52 Properties of our sample galaxies
tabled2.dat 170 98 Physical properties of the compact and extended
blobs
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Byte-by-byte Description of file: tabled1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- --- [ID]
3- 5 I3 --- ID [107/915] Galaxy identifier
7- 18 F12.8 deg RAdeg Right ascension (J2000)
20- 29 F10.8 deg DEdeg Declination (J2000)
31- 35 F5.3 --- z Redshift
37- 41 F5.3 --- e_z Error on z
43- 45 F3.1 kpc Re Effective radius
47- 50 F4.1 [Msun] logM* Logarithm of stellar mass estimated from
the SED fitting
52- 54 F3.1 [Msun/yr] logSFR Logarithm of star formation rate from SED
fitting
56- 58 F3.1 mag E(B-V) Reddening estimated from the Balmer
decrement when longslit Subaru/MOIRCS
spectra are available, from SED fitting
otherwise
60- 62 F3.1 mag e_E(B-V) Error on E(B-V)
64 A1 --- l_Z Limit flag on Z
66- 69 F4.2 [-] Z ? Gas-phase metallicity 12+log(O/H)
estimated from the [OIII]/[OII]
line ratio, when the lines were detected
71- 74 F4.2 [-] E_Z ? Upper error on Z
76- 79 F4.2 [-] e_Z ? Lower error on Z
81- 85 F5.2 10-21mW/m2 F140W Observed galaxy flux in the F140W
broad-band filter
87- 90 F4.2 10-21mW/m2 e_F140W Error on F140W
92- 96 F5.2 10-21mW/m2 F105W ? Observed galaxy flux in the F105W
broad-band filter
98-101 F4.2 10-21mW/m2 e_F105W ? Error on F105W
103-107 F5.2 10-21mW/m2 F606W Observed galaxy flux in the F606W
broad-band filter
109-112 F4.2 10-21mW/m2 e_F606W Error on F606W
114 A1 --- l_F[OII] Limit flag on F[OII]
116-120 F5.2 10-17mW/m2 F[OII] ? Observed [OII] flux of the galaxy
122-125 F4.2 10-17mW/m2 e_F[OII] ? Error on F[OII]
127 A1 --- l_FHbeta Limit flag on FHbeta
129-133 F5.2 10-17mW/m2 FHbeta ? Observed Hβ flux of the galaxy
135-138 F4.2 10-17mW/m2 e_FHbeta ? Error on FHbeta
140 A1 --- l_F[OIII] Limit flag on F[OIII]
142-146 F5.2 10-17mW/m2 F[OIII] ? Observed [OIII] flux of the galaxy
148-151 F4.2 10-17mW/m2 e_F[OIII] ? Error on F[OIII]
153-157 F5.2 10-17mW/m2 FHalpha ? Observed Hα flux of the galaxy
159-162 F4.2 10-17mW/m2 e_FHalpha ? Error on FHalpha
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Byte-by-byte Description of file: tabled2.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 2 A2 --- --- [ID]
3- 5 I3 --- ID [123/915] Galaxy identifier
7 A1 --- blob [ce] Compact 'c' or extended 'e' blob
9 A1 --- l_F140W Limit flag on F140W
11- 16 F6.2 10-21mW/m2 F140W Observed blob flux in the F140W broad-band
filter
18- 21 F4.2 10-21mW/m2 e_F140W ? Error on F140W
23 A1 --- l_F105W Limit flag on F105W
25- 30 F6.2 10-21mW/m2 F105W ? Observed blob flux in the F105W
broad-band filter
32- 35 F4.2 10-21mW/m2 e_F105W ? Error on F105W
37 A1 --- l_F606W Limit flag on F606w
39- 45 F7.2 10-21mW/m2 F606W Observed blob flux in the F606W broad-band
filter
47- 51 F5.2 10-21mW/m2 e_F606W ? Error on F606W
53 A1 --- l_F[OII] Limit flag on F[OII]
55- 58 F4.2 10-17mW/m2 F[OII] ? Observed [OII] flux of the blob
60- 63 F4.2 10-17mW/m2 e_F[OII] ? Error on F[OII]
65 A1 --- l_FHbeta Limit flag on FHbeta
67- 70 F4.2 10-17mW/m2 FHbeta ? Observed Hβ flux of the blob
72- 75 F4.2 10-17mW/m2 e_FHbeta ? Error on FHbeta
77 A1 --- l_F[OIII] Limit flag on F[OIII]
79- 82 F4.2 10-17mW/m2 F[OIII] ? Observed [OIII] flux of the blob
84- 87 F4.2 10-17mW/m2 e_F[OIII] ? Error on F[OIII]
89 A1 --- l_FHalpha Limit flag on FHalpha
91- 95 F5.2 10-17mW/m2 FHalpha ? Observed Hα flux of the blob
97-100 F4.2 10-17mW/m2 e_FHalpha ? Error on FHalpha
102 A1 --- l_M* Limit flag on M*
104-109 F6.2 10+8Msun M* ? Stellar mass
111-116 F6.2 10+8Msun e_M* ? Error on M*
118 A1 --- l_SFR Limit flag on SFR
120-124 F5.1 Msun/yr SFR ? Star formation rate
126-131 F6.1 Msun/yr e_SFR ? Error on SFR
133 A1 --- l_Age Limit flag on Age
135-140 F6.2 10+7yr Age ? Age
142-147 F6.2 10+7yr E_Age ? Upper error on Age
149-153 F5.2 10+7yr e_Age ? Lower error on Age
155 A1 --- l_Z Limit flag on Z
157-160 F4.2 [-] Z ? Gas-phase metallicity 12+log(O/H)
estimated from the [OIII]/[OII]
line ratio, when the lines were detected
162-165 F4.2 [-] E_Z ? Upper error on Z
167-170 F4.2 [-] e_Z ? Lower error on Z
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History:
From electronic version of the journal
(End) Ana Fiallos [CDS] 11-Jan-2023