J/A+A/625/A102 MUSE datacube of MRC 0943-242 (Kolwa+, 2019)
MUSE unravels the ionisation and origin of metal-enriched absorbers in the gas
halo of a z = 2.92 radio galaxy.
Kolwa S., Vernet J., De Breuck C., Villar-Martin M., Humphrey A.,
Arrigoni-Battaia F., Gullberg B., Falkendal T., Drouart G., Lehnert M.,
Wylezalek D., Man A.
<Astron. Astrophys. 625, A102 (2019)>
=2019A&A...625A.102K 2019A&A...625A.102K (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, radio
Keywords: galaxies: active - galaxies: individual: MRC 0943-242 -
galaxies: halos - ISM: jets and outflows
Abstract:
We have used the Multi-Unit Spectroscopic Explorer (MUSE) to study the
circumgalactic medium (CGM) of a z=2.92 radio galaxy, MRC 0943-242 by
parametrising its emitting and absorbing gas. In both Lyα
λ1216 and HeII λ1640 lines, we observe emission with
velocity shifts of Δv≃-1000km/s from the systemic redshift of
the galaxy. These blueshifted components represent kinematically
perturbed gas that is aligned with the radio axis, which we interpret
as jet-driven outflows. Three of the four known Ly absorbers are
detected at the same velocity as CIV λλ1548,1551 and
NV λλ1239,1243 absorbers, proving that the gas is
metal-enriched more so than previously thought. At the velocity of a
strong Lyα absorber with an HI column of NHI/cm-2=1019.2
and velocity shift of Deltav≃-400km/s, we also detect SiII
λ1260 and SiII λ1527 absorption, which suggests that the
absorbing gas is ionisation bounded. With the added sensitivity of
this MUSE observation, we are more capable of adding constraints to
absorber column densities and consequently determining what powers
their ionisation. To do this, we obtain photoionisation grid models in
cloudy which show that AGN radiation is capable of ionising the gas
and producing the observed column densities in a gas of metallicity of
Z/Z☉~=0.01 with a nitrogen abundance a factor of 10 greater than
that of hydrogen. This metal-enriched absorbing gas, which is also
spatially extended over a projected distance of r≳60kpc, is likely to
have undergone chemical enrichment through stellar winds that have
swept up metals from the interstellar-medium and deposited them in the
outer regions of the galaxy's halo.
Description:
MUSE datacube of the z=2.92 radio galaxy, MRC 0943-242.
Objects:
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RA (2000) DE Designation(s)
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09 45 32.7 -24 28 49 MRC 0943-242 = PMN J0945-2429
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File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
list.dat 168 1 Information on fits 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 F3.1 arcsec/pix scale Scale of the image
24- 26 I3 --- Nx Number of pixels along X-axis
28- 30 I3 --- Ny Number of pixels along Y-axis
32- 35 I4 --- Nz Number of pixels along Z-axis
37- 59 A23 "datime" Obs.date Observation date
61- 67 F7.2 0.1nm blambda Lower value of wavelength interval
69- 74 F6.1 0.1nm Blambda Upper value of wavelength interval
76- 79 F4.2 0.1nm dlambda Wavelength resolution
81- 87 I7 Kibyte size Size of FITS file
89-114 A26 --- FileName Name of FITS file, in subdirectory fits
116-168 A53 --- Title Title of the FITS file
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Acknowledgements:
Sthabile Kolwa, skolwa(at)eso.org
(End) Patricia Vannier [CDS] 23-Apr-2019