J/ApJ/874/53 COSMOS galaxies with ALMA 345.7GHz & 342.3GHz obs. (Betti+, 2019)
Environmental effect on the interstellar medium in galaxies across the cosmic
web at z=0.73.
Betti S.K., Pope A., Scoville N., Yun M.S., Aussel H., Kartaltepe J.,
Sheth K.
<Astrophys. J., 874, 53-53 (2019)>
=2019ApJ...874...53B 2019ApJ...874...53B (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, IR; Millimetric/submm sources; Interstellar medium
Keywords: galaxies: evolution; galaxies: ISM; submillimeter: galaxies
Abstract:
We present new Atacama Large Millimeter Array (ALMA) dust continuum
observations of 101 log(M*/M☉)>9.5 galaxies in the COSMOS
field to study the effect of the environment on the interstellar
medium at z∼0.7. At this redshift, our targets span a wide range of
environments allowing for a diverse sample of galaxies with densities
of Σ=0.16-10.5Mpc-2 (per Δz=0.024). Using the ALMA
observations, we calculate the total interstellar medium (ISM) mass
(MISM) and look for depletion as a function of galaxy density in
order to understand the quenching or triggering of star formation in
galaxies in different environments. MISM is found to have a small
dependence on the environment, while the depletion timescale remains
constant (∼200Myr) across all environments. We find elevated MISM
values at intermediate densities and lower values at high densities
compared to low (field) densities. Our observed evolution in gas
fraction with density in this single redshift slice is equivalent to
the observed evolution with cosmic time over 2-3Gyr. To explain the
change in the gas mass fraction seen in galaxies in intermediate and
high densities, these results suggest environmental processes such as
mergers and ram pressure stripping are likely playing a role in dense
filamentary cluster environments.
Description:
Our sample of 101 galaxies is selected from the COSMOS 2deg2 survey
(Scoville+ 2007ApJS..172....1S 2007ApJS..172....1S), which has multiwavelength coverage
from 37 bands, including deep Herschel (PACS and SPIRE) imaging from
100 to 500um. Accurate photometric redshifts in the COSMOS field have
been derived from UV through near-infrared (near-IR) photometry from
34 bands, which is described in detail by Ilbert+ (2013, J/A+A/556/A55)
and Laigle+ (2016, J/ApJS/224/24).
We measure the dust continuum for our sample with ALMA Cycle 3
observations (2015.1.00055.S; PI: Pope). The 101 galaxies were
separated into two ALMA science goals: galaxies with z=0.72-0.741 in
the first science goal (SG1, 65 sources), and galaxies with
z=0.741-0.76 in the second science goal (SG2, 36 sources). Both
science goals were observed in Band 7 with SG1 observations taken
between 2016 January 2 and 5 (ν=345.7GHz, bandwidth of 7.475GHz)
and SG2 observations taken between 2016 January 26 and April 27
(ν=342.3GHz, bandwidth of 7.425GHz). On-source integration time for
both science goals was 3 minutes per galaxy.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 127 101 Sample properties and measurements
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See also:
II/284 : COSMOS Multi-Wavelength Photometry Catalog (Capak+, 2007)
VI/139 : Herschel Observation Log (Herschel Science Centre, 2013)
J/A+A/327/522 : Molecular gas content of spiral galaxies (Boselli+ 1997)
J/ApJS/172/70 : zCOSMOS-bright catalog, DR3 (Lilly+, 2007)
J/A+A/532/A90 : PACS Evolutionary Probe (PEP-DR1) catalogs (Lutz+, 2011)
J/A+A/533/A119 : GOODS-Herschel North and South catalogs (Elbaz+, 2011)
J/ApJ/768/74 : PHIBSS: CO obs. of star-forming galaxies (Tacconi+, 2013)
J/A+A/556/A55 : Multi-color phot. of star-forming galaxies (Ilbert+, 2013)
J/A+A/557/A66 : Effective SEDs of IR galaxies at various z (Bethermin+, 2013)
J/ApJ/775/78 : Lyman limit absorption systems in z∼3 QSOs (Fumagalli+, 2013)
J/ApJ/783/84 : ALMA obs. in 107 galaxies at z=0.2-2.5 (Scoville+, 2014)
J/ApJS/221/11 : CANDELS visual classifications for GOODS-S (Kartaltepe+, 2015)
J/ApJ/820/83 : ALMA galaxies in the COSMOS survey field (Scoville+, 2016)
J/ApJS/224/24 : The COSMOS2015 catalog (Laigle+, 2016)
J/ApJ/837/16 : Cosmic web of galaxies in the COSMOS field (Darvish+, 2017)
J/A+A/608/A15 : ALMA survey of submm galaxies in COSMOS field (Brisbin+, 2017)
Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1 I1 --- Bin [1/3] Bin number (1)
3- 7 I5 --- ID [1460/65511] Identifier
9 I1 --- SG [1/2] ALMA science goal
11- 22 F12.8 deg RAdeg [149.5/150.8] Right ascension (J2000)
24- 33 F10.8 deg DEdeg [1.6/2.8] Declination (J2000)
35- 39 F5.3 --- zspec [0.72/0.76] Spectroscopic redshift
41- 45 F5.2 Mpc-2 Sigma [0.17/10.5] Local galaxy density, Σ
47- 52 F6.2 Msun/yr SFR-IR [17/252.5] IR star formation rate
54- 57 F4.2 Msun/yr SFR-UV [0/7] UV star formation rate
59- 64 F6.2 Msun/yr SFR-tot [17/254] Total star formation rate
66- 70 F5.2 [Msun] logMs [9.4/11.2] log of stellar mass
72- 76 F5.3 mJy/beam rms [0.15/0.24] Average rms of tapered images
78 A1 --- l_Snu Limit flag on Snu
80- 83 F4.2 mJy Snu [0.26/1.2] Flux measurement, Sν
85- 88 F4.2 mJy e_Snu [0.1/0.2]? Snu uncertainty
90 A1 --- l_MISM Limit flag on MISM
92- 95 F4.2 10+10Msun MISM [0.99/4.8] Total ISM mass (see Equation 4)
97- 100 F4.2 10+10Msun e_MISM [0.36/0.8]? MISM uncertainty
102 A1 --- l_logSFE Limit flag on logSFE
104- 108 F5.2 yr-1 logSFE [-9.1/-8.1] log of star formation efficiency
110- 113 F4.2 yr-1 e_logSFE [0.06/0.21]? logSFE uncertainty
115 A1 --- l_fgas Limit flag on fgas
117- 120 F4.2 --- fgas [0.09/0.81] Observed gas fraction,
fgas=MISM/(MISM+Ms)
122- 125 F4.2 --- e_fgas [0.03/0.28]? fgas uncertainty
127 I1 --- Note [1/3] Note (2)
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Note (1): Bin number as follows:
1 = low Σ (<1.2Mpc-2); 61 galaxies
2 = intermediate Σ (1.2-2.6Mpc-2); 25 galaxies
3 = high Σ (>2.6Mpc-2); 15 galaxies
Note (2): Note as follows:
1 = flux found from integrated aperture;
2 = flux found from peak pixel;
3 = 3σ upper limit
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History:
From electronic version of the journal
(End) Emmanuelle Perret [CDS] 23-Oct-2023