6 research outputs found
The physics of Galaxy Evolution with SPICA observations
The evolution of galaxies at Cosmic Noon (redshift 1<z<3) passed through a
dust-obscured phase, during which most stars formed and black holes in galactic
nuclei started to shine, which cannot be seen in the optical and UV, but it
needs rest frame mid-to-far IR spectroscopy to be unveiled. At these
frequencies, dust extinction is minimal and a variety of atomic and molecular
transitions, tracing most astrophysical domains, occur. The future IR space
telescope mission, SPICA, currently under evaluation for the 5th Medium Size
ESA Cosmic Vision Mission, fully redesigned with its 2.5 m mirror cooled down
to T < 8K will perform such observations. SPICA will provide for the first time
a 3-dimensional spectroscopic view of the hidden side of star formation and
black hole accretion in all environments, from voids to cluster cores over 90%
of cosmic time. Here we outline what SPICA will do in galaxy evolution studies.Comment: Contributed talk at the IAU Symp 359 Galaxy Evolution and Feedback
Across Different Environments, 2020 March 2-6, Bento Concalves, Brazil. arXiv
admin note: text overlap with arXiv:1911.1218
CO kinematics unveil outflows plausibly driven by a young jet in the gigahertz peaked radio core of NGC 6328
We report the detection of outflowing molecular gas in the center of the
nearby (z = 0.014) massive radio galaxy NGC 6328. The radio core of the
galaxy, PKS B1718-649, is identified as a gigahertz peaked spectrum
source with a compact (2 pc) double radio lobe morphology. We used ALMA
CO(2-1) and CO(3-2) observations at 100 pc resolution to study the gas
kinematics up to similar to 5kpc from the galaxy center. While the bulk
of the molecular gas is settled in a highly warped disk, in the inner
300 pc of the disk and along with the orientation of the radio jet, we
identified high-excitation and high-velocity gas that cannot be
attributed to any regular kinematic component based on our detailed 3D
modeling of the ALMA data. The high-velocity dispersion in the gas also
suggests that it is not part of an inflowing, shredding structure. These
results suggest the presence of a molecular outflow of 3-8 solar masses
per year. The outflow possibly originated from the interaction of the
jet with the dense interstellar medium, even though the radio emission
is detected closer to the center than the outflow. In this sense, this
source resembles NGC 1377, 4C31.04, and ESO 420-G13, in which the
outflows are linked to faint or past jet activity
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Herschel/PACS OH Spectroscopy of Seyfert, LINER, and Starburst Galaxies*
We investigated the 65m, 71m, 79m, 84m, 119m, and
163m OH doublets of 178 local (0 < < 0.35) galaxies. They were
observed using the /PACS spectrometer, including Seyfert galaxies,
LINERs, and star-forming galaxies. We observe these doublets exclusively in
absorption (OH71), primarily in absorption (OH65, OH84), mostly in emission
(OH79), only in emission (OH163) and an approximately even mix of the both
(OH119). In 19 galaxies we find P-Cygni or reverse P-Cygni line profiles in the
OH doublets. We use several galaxy observables to probe spectral
classification, brightness of a central AGN/starburst component, and radiation
field strength. We find that OH79, OH119, and OH163 are more likely to display
strong emission for bright, unobscured AGN. For less luminous, obscured AGN and
non-active galaxies, we find populations of strong absorption (OH119), weaker
emission (OH163), and a mix of weak emission and weak absorption (OH79). For
OH65, OH71 and OH84, we do not find significant correlations with the
observables listed above. We do find relationships between OH79 and OH119 with
both the 9.7m silicate feature and Balmer decrement dust extinction
tracers in which more dust leads to weaker emission / stronger absorption. The
origin of emission for the observed OH doublets, whether from collisional
excitation, or from radiative pumping by infrared photons, is discussed
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Mid-IR cosmological spectrophotometric surveys from space: Measuring AGN and star formation at the cosmic noon with a SPICA-like mission
Abstract
We use the SPace Infrared telescope for Cosmology and Astrophysics (SPICA) project as a template to demonstrate how deep spectrophotometric surveys covering large cosmological volumes over extended fields (1â
) with a mid-IR imaging spectrometer (17â
36\, \rm{\rm{\upmu m}}
) in conjunction with deep
70\, \rm{\rm{\upmu m}}
photometry with a far-IR camera, at wavelengths which are not affected by dust extinction can answer the most crucial questions in current galaxy evolution studies. A SPICA-like mission will be able for the first time to provide an unobscured three-dimensional (3D, i.e. x, y, and redshift z) view of galaxy evolution back to an age of the universe of less than
2 Gyrs, in the mid-IR rest frame. This survey strategy will produce a full census of the Star Formation Rate (SFR) in the universe, using polycyclic aromatic hydrocarbons (PAH) bands and fine-structure ionic lines, reaching the characteristic knee of the galaxy luminosity function, where the bulk of the population is distributed, at any redshift up to
. Deep follow-up pointed spectroscopic observations with grating spectrometers onboard the satellite, across the full IR spectral range (17â
210\, \rm{\rm{\upmu m}}
), would simultaneously measure Black Hole Accretion Rate (BHAR), from high-ionisation fine-structure lines, and SFR, from PAH and low- to mid-ionisation lines in thousands of galaxies from solar to low metallicities, down to the knee of their luminosity functions. The analysis of the resulting atlas of IR spectra will reveal the physical processes at play in evolving galaxies across cosmic time, especially its heavily dust-embedded phase during the activity peak at the cosmic noon (
â3), through IR emission lines and features that are insensitive to the dust obscuration
ReveaLLAGN 0: First look at JWST MIRI data of Sombrero and NGC 1052
International audienceWe present the first results from the Revealing Low-Luminosity Active Galactic Nuclei (ReveaLLAGN) survey, a JWST survey of seven nearby LLAGNs. We focus on two observations with the Mid-Infrared Instrument (MIRI)'s Medium-Resolution Spectrometer of the nuclei of NGC 1052 and Sombrero (NGC 4594/M104). We also compare these data to public JWST data of higher-luminosity AGNs, NGC 7319 and NGC 7469. JWST clearly separates the AGN spectrum from the galaxy light even in Sombrero, the faintest target in our survey; the AGN components have very red spectra. We find that the emission-line widths in both NGC 1052 and Sombrero increase with increasing ionization potential, with FWHM > 1000 km sâ1 for lines with ionization potential âł 50 eV. These lines are also significantly blueshifted in both LLAGNs. The high-ionization-potential lines in NGC 7319 show neither broad widths nor significant blueshifts. Many of the lower-ionization-potential emission lines in Sombrero show significant blue wings extending >1000 km sâ1. These features and the emission-line maps in both galaxies are consistent with outflows along the jet direction. Sombrero has the lowest-luminosity high-ionization-potential lines ([Ne V] and [O IV]) ever measured in the mid-infrared, but the relative strengths of these lines are consistent with higher-luminosity AGNs. On the other hand, the [Ne V] emission is much weaker relative to the [Ne III] and [Ne II] lines of higher-luminosity AGNs. These initial results show the great promise that JWST holds for identifying and studying the physical nature of LLAGNs