In Tombesi et al., we reported the first direct evidence for a quasar accretion disk wind driving a massive (>100 M yr−1) molecular outflow. The target was F11119+3257, an ultraluminous infrared ...galaxy (ULIRG) with unambiguous type 1 quasar optical broad emission lines. The energetics of the accretion disk wind and molecular outflow were found to be consistent with the predictions of quasar feedback models where the molecular outflow is driven by a hot energy-conserving bubble inflated by the inner quasar accretion disk wind. However, this conclusion was uncertain because the mass outflow rate, momentum flux, and mechanical power of the outflowing molecular gas were estimated from the optically thick OH 119 m transition profile observed with Herschel. Here, we independently confirm the presence of the molecular outflow in F11119+3257, based on the detection of ∼ 1000 km s−1 blue- and redshifted wings in the CO(1−0) emission line profile derived from deep ALMA observations obtained in the compact array configuration (∼2 8 resolution). The broad CO(1−0) line emission appears to be spatially extended on a scale of at least ∼7 kpc from the center. Mass outflow rate, momentum flux, and mechanical power of (80-200) M yr−1, (1.5-3.0) LAGN/c, and (0.15-0.40)% , respectively, are inferred from these data, assuming a CO-to-H2 conversion factor appropriate for a ULIRG (R7 is the radius of the outflow normalized to 7 kpc, and LAGN is the AGN luminosity). These rates are time-averaged over a flow timescale of 7 × 106 yr. They are similar to the OH-based rates time-averaged over a flow timescale of 4 × 105 yr, but about a factor of 4 smaller than the local ("instantaneous"; 105 yr) OH-based estimates cited in Tombesi et al. The implications of these new results are discussed in the context of time-variable quasar-mode feedback and galaxy evolution. The need for an energy-conserving bubble to explain the molecular outflow is also reexamined.
ABSTRACT
We report the results from a comprehensive study of 74 ultraluminous infrared
galaxies (ULIRGs) and 34 Palomar-Green (PG) quasars within
z
∼
0.3 observed with the
Spitzer
Infrared ...Spectrograph (IRS). The
contribution of nuclear activity to the bolometric luminosity in these systems
is quantified using six independent methods that span a range in wavelength and
give consistent results within ∼±10%–15% on average. This agreement suggests
that deeply buried active galactic nuclei (AGNs) invisible to
Spitzer
IRS but bright in the far-infrared are not common
in this sample. The average derived AGN contribution in ULIRGs is ∼35%–40%,
ranging from ∼15%–35% among “cool”
(
f
25
/
f
60
⩽ 0.2)
optically classified H
ii
-like and LINER ULIRGs to ∼50 and ∼75% among
warm Seyfert 2 and Seyfert 1 ULIRGs, respectively. This number exceeds ∼80% in
PG QSOs. ULIRGs fall in one of three distinct AGN classes: (1) objects with
small extinctions and large polycyclic aromatic hydrocarbon (PAH) equivalent
widths are highly starburst-dominated; (2) systems with large extinctions and
modest PAH equivalent widths have larger AGN contributions, but still tend to be
starburst-dominated; and (3) ULIRGs with both small extinctions and small PAH
equivalent widths host AGN that are at least as powerful as the starbursts. The
AGN contributions in class 2 ULIRGs are more uncertain than in the other
objects, and we cannot formally rule out the possibility that these objects
represent a physically distinct type of ULIRGs. A morphological trend is seen
along the sequence (1)–(2)–(3), in general agreement with the standard ULIRG−QSO
evolution scenario and suggestive of a broad peak in extinction during the
intermediate stages of merger evolution. However, the scatter in this sequence,
including the presence of a significant number of AGN-dominated systems prior to
coalescence and starburst-dominated but fully merged systems, implies that black
hole accretion, in addition to depending on the merger phase, also has a strong
chaotic/random component, as in local AGNs.
ABSTRACT New near- and far-ultraviolet (NUV and FUV) Hubble Space Telescope spectra of Mrk 231, the nearest quasar known, are combined with ground-based optical spectra to study the remarkable ...dichotomy between the FUV and NUV-optical spectral regions in this object. The FUV emission-line features are faint, broad, and highly blueshifted (up to ∼7000 km s−1), with no significant accompanying absorption. In contrast, the profiles of the NUV absorption features resemble those of the optical Na i D, He i, and Ca ii H and K lines, exhibiting broad blueshifted troughs that overlap in velocity space with the FUV emission-line features and indicate a dusty, high-density and patchy broad absorption line (BAL) screen covering ∼90% of the observed continuum source at a distance 2-20 pc. The FUV continuum emission does not show the presence of any obvious stellar features and is remarkably flat compared with the steeply declining NUV continuum. The NUV (FUV) features and continuum emission have not varied significantly over the past ∼22 (3) years and are unresolved on scales ∼40 (170) pc. These results favor an active galactic nucleus origin for the NUV-FUV line and continuum emission. The observed FUV line emission is produced in the outflowing BAL cloud system, while the Balmer lines arise primarily from the standard broad line region seen through the dusty BAL screen. Our data are inconsistent with the recently proposed binary black hole model. We argue instead that Mrk 231 is the nearest example of weak-lined "wind-dominated" quasars with high Eddington ratios and geometrically thick ("slim") accretion disks; these quasars are likely more common in the early universe.
Abstract
We present results on the properties of extreme gas outflows in massive (
M
*
∼ 10
11
M
⊙
), compact, starburst (star formation rate, SFR∼ 200
M
⊙
yr
−1
) galaxies at
z
= 0.4–0.7 with very ...high star formation surface densities (Σ
SFR
∼ 2000
M
⊙
yr
−1
kpc
−2
). Using optical Keck/HIRES spectroscopy of 14 HizEA starburst galaxies, we identify outflows with maximum velocities of 820–2860 km s
−1
. High-resolution spectroscopy allows us to measure precise column densities and covering fractions as a function of outflow velocity and characterize the kinematics and structure of the cool gas outflow phase (
T
∼ 10
4
K). We find substantial variation in the absorption profiles, which likely reflects the complex morphology of inhomogeneously distributed, clumpy gas and the intricacy of the turbulent mixing layers between the cold and hot outflow phases. There is not a straightforward correlation between the bursts in the galaxies’ star formation histories and their wind absorption line profiles, as might naively be expected for starburst-driven winds. The lack of strong Mg
ii
absorption at the systemic velocity is likely an orientation effect, where the observations are down the axis of a blowout. We infer high mass outflow rates of ∼50–2200
M
⊙
yr
−1
, assuming a fiducial outflow size of 5 kpc, and mass loading factors of
η
∼ 5 for most of the sample. While these values have high uncertainties, they suggest that starburst galaxies are capable of ejecting very large amounts of cool gas that will substantially impact their future evolution.
ABSTRACT
Dusty, neutral outflows and inflows are a common feature of nearby star-forming galaxies. We characterize these flows in eight galaxies – mostly active galactic nuclei (AGN) – selected for ...their widespread Na i D signatures from the Siding Spring Southern Seyfert Spectroscopic Snapshot Survey (S7). This survey employs deep, wide field-of-view (FOV) integral field spectroscopy at moderate spectral resolution (R = 7000 at Na i D). We significantly expand the sample of sightlines in external galaxies in which the spatially resolved relationship has been studied between cool, neutral gas properties – N(Na i), Weq(Na i D) – and dust – E(B − V) from both stars and gas. Our sample shows strong, significant correlations of total Weq with E(B − V)⋆ and g − i colour within individual galaxies; correlations with E(B − V)gas are present but weaker. Regressions yield slope variations from galaxy to galaxy and intrinsic scatter ∼1 Å. The sample occupies regions in the space of N(Na i) and $W_\mathrm{eq}^\mathrm{abs}$ versus E(B − V)gas that are consistent with extrapolations from other studies to higher colour excess E(B − V)gas ∼ 1. For perhaps the first time in external galaxies, we detect inverse P Cygni profiles in the Na i D line, presumably due to inflowing gas. Via Doppler-shifted Na i D absorption and emission lines, we find ubiquitous flows that differ from stellar rotation by $\gtrsim$100 km s−1 or have $|v_{\mathrm{ abs}} - v_{\mathrm{ em}}|\gtrsim 100$ km s−1. Inflows and outflows extend towards the edge of the detected stellar disc/FOV, together subtend 10–40 per cent of the projected disc, and have similar mean N(Na i) and Weq(Na i D). Outflows are consistent with minor axis or jet-driven flows, while inflows tend towards the projected major axis. The inflows may result from non-axisymmetric potentials, tidal motions, or halo infall.
Abstract
The Makani galaxy hosts the poster child of a galactic wind on scales of the circumgalactic medium. It consists of a two-episode wind in which the slow, outer wind originated 400 Myr ago ...(Episode I;
R
I
= 20 − 50 kpc) and the fast, inner wind is 7 Myr old (Episode II;
R
II
= 0 − 20 kpc). While this wind contains ionized, neutral, and molecular gas, the physical state and mass of the most extended phase—the warm, ionized gas—are unknown. Here we present Keck optical spectra of the Makani outflow. These allow us to detect hydrogen lines out to
r
= 30–40 kpc and thus constrain the mass, momentum, and energy in the wind. Many collisionally excited lines are detected throughout the wind, and their line ratios are consistent with 200–400 km s
−1
shocks that power the ionized gas, with
v
shock
=
σ
wind
. Combining shock models, density-sensitive line ratios, and mass and velocity measurements, we estimate that the ionized mass and outflow rate in the Episode II wind could be as high as those of the molecular gas:
M
II
H
II
∼
M
II
H
2
=
(
1
−
2
)
×
10
9
M
⊙
and
dM
/
dt
II
H
II
∼
dM
/
dt
II
H
2
=
170
−
250
M
⊙
yr
−1
. The outer wind has slowed, so that
dM
/
dt
I
H
II
∼
10
M
⊙
yr
−1
, but it contains more ionized gas,
M
I
H
II
=
5
×
10
9
M
⊙
. The momentum and energy in the recent Episode II wind imply a momentum-driven flow (
p
“boost” ∼7) driven by the hot ejecta and radiation pressure from the Eddington-limited, compact starburst. Much of the energy and momentum in the older Episode I wind may reside in a hotter phase, or lie further into the circumgalactic medium.
We present observations of NGC 839 made with the Wide Field Spectrograph on the ANU 2.3 m telescope. Our data cover a region 25'' x 60'' at a spatial resolution of {approx}1.''5. The long axis of the ...field is aligned with the superwind we have discovered in this starburst galaxy. The data cover the range of 3700-7000 A, with a spectral resolution R {approx}7000 in the red and R {approx}3000 in the blue. We find that the stellar component of the galaxy is strongly dominated by a fast rotating intermediate-age ({approx}400 Myr) A-type stellar population, while the gas is concentrated in a bi-conical polar funnel. We have generated flux distributions, emission line ratio diagnostics, and velocity maps in both emission and absorption components. We interpret these in the context of a new grid of low-velocity shock models appropriate for galactic-scale outflows. These models fit the data remarkably well, providing for the first time model diagnostics for shocks in superwinds and strongly suggesting that shock excitation is largely responsible for the extended LINER emission in the outflowing gas in NGC 839. Our work may have important implications both for extended LINER emission seen in other galaxies and in the interpretation of objects with 'composite' spectra. Finally, we present a scenario for the formation of E+A galaxies based upon our observations of NGC 839 and its relation to M82.
Abstract
We investigate galactic winds in the HizEA galaxies, a collection of 46 late-stage galaxy mergers at
z
= 0.4–0.8, with stellar masses of
log
(
M
*
/
M
⊙
)
=
10.4
–
11.5
, star formation ...rates (SFRs) of 20–500
M
⊙
yr
−1
, and ultra-compact (a few 100 pc) central star-forming regions. We measure their gas kinematics using the Mg
ii
λ
λ
2796,2803 absorption lines in optical spectra from MMT, Magellan, and Keck. We find evidence of outflows in 90% of targets, with maximum outflow velocities of 550–3200 km s
−1
. We combine these data with ten samples from the literature to construct scaling relations for outflow velocity versus SFR, star formation surface density (Σ
SFR
),
M
*
, and SFR/
M
*
. The HizEA galaxies extend the dynamic range of the scaling relations by a factor of ∼2–4 in outflow velocity and an order of magnitude in SFR and Σ
SFR
. The ensemble scaling relations exhibit strong correlations between outflow velocity, SFR, SFR/
R
, and Σ
SFR
, and weaker correlations with
M
*
and SFR/
M
*
. The HizEA galaxies are mild outliers on the SFR and
M
*
scaling relations, but they connect smoothly with more typical star-forming galaxies on plots of outflow velocity versus SFR/
R
and Σ
SFR
. These results provide further evidence that the HizEA galaxies’ exceptional outflow velocities are a consequence of their extreme star formation conditions rather than hidden black hole activity, and they strengthen previous claims that Σ
SFR
is one of the most important properties governing the velocities of galactic winds.
Abstract
Extremely red quasars, with bolometric luminosities exceeding 10
47
erg s
−1
, are a fascinating high-redshift population that is absent in the local universe. They are the best candidates ...for supermassive black holes accreting at rates at or above the Eddington limit, and they are associated with the most rapid and powerful outflows of ionized gas known to date. They are also hosted by massive galaxies. Here we present the first integral field unit observations of a high-redshift quasar obtained by the Near Infrared Spectrograph on board the James Webb Space Telescope (JWST), which targeted SDSS J165202.64+172852.3, an extremely red quasar at
z
= 2.94. The JWST observations reveal extended ionized gas—as traced by O
iii
λ
5007 Å—in the host galaxy of the quasar, its outflow, and the circumgalactic medium. The complex morphology and kinematics imply that the quasar resides in a very dense environment with several interacting companion galaxies within projected distances of 10–15 kpc. The high density of the environment and the large velocities of the companion galaxies suggest that this system may represent the core of a forming cluster of galaxies. The system is a good candidate for a merger of two or more dark matter halos, each with a mass of a few 10
13
M
⊙
, and potentially traces one of the densest knots at
z
∼ 3.
To understand the role that active galactic nuclei (AGN) feedback plays in galaxy evolution, we need in-depth studies of the multi-phase structure and energetics of galaxy-wide outflows. In this ...work, we present new, deep (∼50 h) NOEMA CO(1-0) line observations of the molecular gas in the powerful outflow driven by the AGN in the ultra-luminous infrared galaxy IRAS F08572+3915. We spatially resolve the outflow, finding that its most likely configuration is a wide-angle bicone aligned with the kinematic major axis of the rotation disk. The molecular gas in the wind reaches velocities up to approximately ±1200 km s
−1
and transports nearly 20% of the molecular gas mass in the system. We detect a second outflow component located ∼6 kpc northwest from the galaxy moving away at ∼900 km s
−1
, which could be the result of a previous episode of AGN activity. The total mass and energetics of the outflow, which includes contributions from the ionized, neutral, and warm and cold molecular gas phases, is strongly dominated by the cold molecular gas. In fact, the molecular mass outflow rate is higher than the star formation rate, even if we only consider the gas in the outflow that is fast enough to escape the galaxy, which accounts for ∼40% of the total mass of the outflow. This results in an outflow depletion time for the molecular gas in the central ∼1.5 kpc region of only ∼3 Myr, a factor of ∼2 shorter than the depletion time by star formation activity.
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