59 research outputs found
A Catalog of 71 Coronal Line Galaxies in MaNGA: [NeV] is an Effective AGN Tracer
Despite the importance of AGN in galaxy evolution, accurate AGN
identification is often challenging, as common AGN diagnostics can be confused
by contributions from star formation and other effects (e.g.,
Baldwin-Phillips-Terlevich diagrams). However, one promising avenue for
identifying AGNs are ``coronal emission lines" (``CLs"), which are highly
ionized species of gas with ionization potentials 100 eV. These CLs may
serve as excellent signatures for the strong ionizing continuum of AGN. To
determine if CLs are in fact strong AGN tracers, we assemble and analyze the
largest catalog of optical CL galaxies using the Sloan Digital Sky Survey's
Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) catalog. We detect
CL emission in 71 MaNGA galaxies, out of the 10,010 unique galaxies from the
final MaNGA catalog, with 5 confidence. In our sample, we measure
[NeV]3347, 3427, [FeVII]3586, 3760,
6086, and [FeX]6374 emission and crossmatch the CL galaxies
with a catalog of AGNs that were confirmed with broad line, X-ray, IR, and
radio observations. We find that [NeV] emission, compared to [FeVII] and [FeX]
emission, is best at identifying high luminosity AGN. Moreover, we find that
the CL galaxies with the least dust extinction yield the most iron CL
detections. We posit that the bulk of the iron CLs are destroyed by dust grains
in the galaxies with the highest [OIII] luminosities in our sample, and that
AGN in the galaxies with low [OIII] luminosities are possibly too weak to be
detected using traditional techniques.Comment: 21 pages, 6 figures, 8 table
Complex AGN feedback in the Teacup galaxy. A powerful ionised galactic outflow, jet-ISM interaction, and evidence for AGN-triggered star formation in a giant bubble
The ~0.1 type-2 QSO J1430+1339 (the 'Teacup') is a complex galaxy showing
a loop of ionised gas ~10 kpc in diameter, co-spatial radio bubbles, a compact
(~1 kpc) jet, and outflow activity. We used VLT/MUSE optical integral field
spectroscopic observations to characterise the properties and effects of the
galactic ionised outflow from kpc up to tens of kpc scales and compare them
with those of the radio jet. We detect a velocity dispersion enhancement (>300
km/s) elongated over several kpc perpendicular to the radio jet, the AGN
ionisation lobes, and the fast outflow, similar to what is found in other
galaxies hosting compact, low-power jets, indicating that the jet strongly
perturbs the host ISM. The mass outflow rate decreases with distance from the
nucleus, from around 100 /yr in the inner 1-2 kpc to <0.1 /yr
at 30 kpc. The ionised mass outflow rate is ~1-8 times higher than the
molecular one, in contrast with what is often quoted in AGN. The driver of the
multi-phase outflow is likely a combination of AGN radiation and the jet. The
outflow mass-loading factor (~5-10) and the molecular gas depletion time
(<10 yr) indicate that the outflow can significantly affect the star
formation and the gas reservoir in the galaxy. However, the fraction of the
ionised outflow that is able to escape the dark matter halo potential is likely
negligible. We detect blue-coloured continuum emission co-spatial with the
ionised gas loop. Here, stellar populations are younger (<100-150 Myr) than in
the rest of the galaxy (~0.5-1 Gyr). This constitutes possible evidence for
star formation triggered at the edge of the bubble due to the compressing
action of the jet and outflow ('positive feedback'), as predicted by theory.
All in all, the Teacup constitutes a rich system in which AGN feedback from
outflows and jets, in both its negative and positive flavours, co-exist.Comment: 26 pages, 16 figures; Astronomy & Astrophysics, in pres
Hubble Space Telescope Observations of [O~III] Emission in Nearby QSO2s: Physical Properties of the Ionised Outflows
We use Hubble Space Telescope (HST)/ Space Telescope Imaging Spectrograph
(STIS) long-slit G430M and G750M spectra to analyse the extended [O~III] 5007A
emission in a sample of twelve nearby (z 1.6 x 10^45
erg s^-1) QSO2s. The purpose of the study is to determine the properties of the
mass outflows of ionised gas and their role in AGN feedback. We measure fluxes
and velocities as functions of radial distances. Using Cloudy models and
ionising luminosities derived from [O~III] 5007A, we are able to estimate the
densities for the emission-line gas. From these results, we derive masses of
[O~III]-emitting gas, mass outflow rates, kinetic energies, kinetic
luminosities, momenta and momentum flow rates as a function of radial distance
for each of the targets. For the sample, masses are several times 10^3 - 10^7
solar masses and peak outflow rates are 9.3 x 10^-3 Msun/yr to 10.3 Msun/yr.
The peak kinetic luminosities are 3.4 x 10^-8 to 4.9 x 10^-4 of the bolometric
luminosity, which does not approach the 5.0 x 10^-3 - 5.0 x 10^-2 range
required by some models for efficient feedback. For Mrk 34, which has the
largest kinetic luminosity of our sample, in order to produce efficient
feedback there would have to be 10 times more [O~III]-emitting gas than we
detected at its position of maximum kinetic luminosity. Three targets show
extended [O~III] emission, but compact outflow regions. This may be due to
different mass profiles or different evolutionary histories.Comment: 14 pages, 11 Figures, accepted for publication in the MNRA
An additive subfamily of enlargements of a maximally monotone operator
We introduce a subfamily of additive enlargements of a maximally monotone
operator. Our definition is inspired by the early work of Simon Fitzpatrick.
These enlargements constitute a subfamily of the family of enlargements
introduced by Svaiter. When the operator under consideration is the
subdifferential of a convex lower semicontinuous proper function, we prove that
some members of the subfamily are smaller than the classical
-subdifferential enlargement widely used in convex analysis. We also
recover the epsilon-subdifferential within the subfamily. Since they are all
additive, the enlargements in our subfamily can be seen as structurally closer
to the -subdifferential enlargement
The AGNIFS survey: spatially resolved observations of hot molecular and ionised outflows in nearby active galaxies
We present the hot molecular and warm ionised gas kinematics for 33 nearby
() X-ray selected active galaxies using the Hm and Br emission lines observed in the K-band with the
Gemini Near-Infrared Field Spectrograph (NIFS). The observations cover the
inner 0.042 kpc of each AGN at spatial resolutions of 4250 pc with a
velocity resolution of 20 . We find
that 31 objects (94 per cent) present a kinematically disturbed region (KDR)
seen in ionised gas, while such regions are observed in hot molecular gas for
25 galaxies (76 per cent). We interpret the KDR as being due to outflows with
masses of 1010 M and 1010 M for the ionised
and hot molecular gas, respectively. The ranges of mass-outflow rates
() and kinetic power () of the outflows are
1010 Myr and 1010 erg
s for the ionised gas outflows, and 1010 M
yr and 1010 erg s for the hot molecular gas
outflows. The median coupling efficiency in our sample is and the estimated momentum fluxes of the outflows
suggest they are produced by radiation-pressure in low-density environment,
with possible contribution from shocks.Comment: 37 pages, published in MNRAS - A few typos in the text and in the
label of Fg 1 were corrected in this versio
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