J/A+A/649/A31 [CCJ2015b] HZ4 [CII] 158um datacube (Herrera-Camus+, 2021)
Kiloparsec view of a typical star-forming galaxy when the Universe was ∼1 Gyr
old. I. Properties of outflow, halo, and interstellar medium.
Herrera-Camus R., Foerster Schreiber N., Genzel R., Tacconi L., Bolatto A.,
Davies R.L., Fisher D., Lutz D., Naab T., Shimizu T., Tadaki K., Uebler H.
<Astron. Astrophys. 649, A31 (2021)>
=2021A&A...649A..31H 2021A&A...649A..31H (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies ; Millimetric/submm sources
Keywords: galaxies: high-redshift - galaxies: ISM - galaxies: structure
Abstract:
We present new Atacama Large Millimeter/Submillimeter Array (ALMA)
observations of the [CII] 158um transition and the dust continuum in
HZ4, a typical star-forming galaxy when the Universe was only ∼1Gyr
old (z∼5.5). Our high ∼0.3" spatial resolution allows us to study the
relationships between [CII] line emission, star formation rate, and
far-infrared emission on spatial scales of ∼2kpc. In the central ∼4kpc
of HZ4 the [CII]/FIR is ∼3x10-3 on global scales as well as on
spatially resolved scales of ∼2kpc, comparable to the ratio observed
in local moderate starburst galaxies such as M82 or M83. For the first
time in an individual normal galaxy at this redshift, we find evidence
for outflowing gas from the central star-forming region in the
direction of the minor axis of the galaxy. The projected velocity of
the outflow is ∼400km/s, and the neutral gas-mass outflow rate is
∼3-6 times higher than the star formation rate in the central region.
Finally, we detect a diffuse component of [CII] emission, or [CII]
halo, that extends beyond the star-forming disk and has a diameter of
∼12kpc. The outflow, which has a velocity approximately half of the
escape velocity of the system, most likely partly fuels the [CII]
extended emission. Together with the kinematic analysis of HZ4
(presented in a forthcoming paper), the analysis supports the
hypothesis that HZ4 is a typical star-forming disk at z∼5 with
interstellar medium conditions similar to present-day galaxies forming
stars at a similar level, driving a galactic outflow that may already
play a role in its evolution.
Description:
Between November 2018 and April 2019 (Cycle 6), HZ4
(R.A. 9:58:28.5, Dec. +2:03:06.7) was observed for 8.4hr in total
(4.7hr on-source) using ALMA as part of project 2018.1.01605.S (PI
Herrera-Camus). The observations were carried out in the C43-4
configuration. We centered one spectral window on the [CII] line
(νrest=1900.537GHz), which for the source is redshifted to
νobs=290.386GHz and falls in Band 7.
Objects:
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RA (2000) DE Designation(s)
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09 58 28.52 +02 03 06.8 HZ4 = [CCJ2015b] HZ4
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 122 1 Information on datacube
fits/* . 1 Datacube
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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- 30 I3 --- Nz Number of pixels along Z-axis
32- 54 A23 "datime" Obs.date Observation date
56- 62 I7 m/s bVRAD Lower value of VRAD interval
64- 69 I6 m/s BVRAD Upper value of VRAD interval
71- 77 F7.1 m/s dVRAD VRAD resolution
79- 84 I6 Kibyte size Size of FITS file
86- 97 A12 --- FileName Name of FITS file, in subdirectory fits
99-122 A24 --- Title Title of the FITS file
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Acknowledgements:
Rodrigo Herrera-Camus, rhc(at)astro-udec.cl
(End) Patricia Vannier [CDS] 30-Apr-2021