We present here AMUSING++: the largest compilation of nearby galaxies observed with the MUSE integral-field spectrograph so far. This collection consists of 635 galaxies from different MUSE projects ...covering the redshift interval 0.0002 < z < 0.1. The sample and its main properties are characterized and described here. It includes galaxies of almost all morphological types, with a good coverage in its color-magnitude diagram, within the stellar mass range between 108 and 1012 M , and with properties resembling those of a diameter-selected sample. The AMUSING++ sample is, therefore, suitable for studying, with unprecendented detail, the properties of nearby galaxies at global and local scales, providing us with more than 50 million individual spectra. We use this compilation to investigate the presence of galactic outflows. We exploit the use of combined emission-line images to explore the shape of the different ionized components and the distribution along classical diagnostic diagrams to disentangle the different ionizing sources across the optical extension of each galaxy. We use the cross-correlation function to estimate the level of symmetry of the emission lines as an indication of the presence of shocks and/or active galactic nuclei. We uncovered a total of 54 outflows, comprising ∼8% of the sample. A large number of the discovered outflows correspond to those driven by active galactic nuclei (∼60%), suggesting some bias in the selection of our sample. No clear evidence was found that outflow host galaxies are highly star-forming, and outflows appear to be found within all galaxies around the star-formation sequence.
We present the stellar surface mass density versus gas metallicity ( capital sigma *-Z) relation for more than 500 000 spatially resolved star-forming resolution elements (spaxels) from a sample of ...653 disc galaxies included in the SDSS IV MaNGA survey. We find a tight relation between these local properties, with higher metallicities as the surface density increases. This relation extends over three orders of magnitude in the surface mass density and a factor of 4 in metallicity. We show that this local relationship can simultaneously reproduce two well-known properties of disc galaxies: their global mass-metallicity relationship and their radial metallicity gradients. We also find that the capital sigma gr; *-Z relation is largely independent of the galaxy's total stellar mass and specific star formation rate (sSFR), except at low stellar mass and high sSFR. These results suggest that in the present-day universe local properties play a key role in determining the gas-phase metallicity in typical disc galaxies.
We present a comparative study of molecular and ionized gas kinematics in nearby galaxies. These results are based on observations from the EDGE survey, which measured spatially resolved 12CO(J = ...1-0) in 126 nearby galaxies. Every galaxy in EDGE has corresponding resolved ionized gas measurements from CALIFA. Using a sub-sample of 17 rotation-dominated, star-forming galaxies where precise molecular gas rotation curves could be extracted, we derive CO and H rotation curves using the same geometric parameters out to 1 Re. We find that ∼75% of our sample galaxies have smaller ionized gas rotation velocities than the molecular gas in the outer part of the rotation curve. In no case is the molecular gas rotation velocity measurably lower than that of the ionized gas. We suggest that the lower ionized gas rotation velocity can be attributed to a significant contribution from extraplanar diffuse ionized gas in a thick, turbulence-supported disk. Using observations of the Hγ transition, also available from CALIFA, we measure ionized gas velocity dispersions and find that these galaxies have sufficiently large velocity dispersions to support a thick ionized gas disk. Kinematic simulations show that a thick disk with a vertical rotation velocity gradient can reproduce the observed differences between the CO and H rotation velocities. Observed line ratios tracing diffuse ionized gas are elevated compared to typical values in the midplane of the Milky Way. In galaxies affected by this phenomenon, dynamical masses measured using ionized gas rotation curves will be systematically underestimated.
Galaxy interaction is considered a key driver of galaxy evolution and star formation (SF) history. In this paper, we present an empirical picture of the radial extent of interaction-triggered SF ...along the merger sequence. The samples under study are drawn from the integral field spectroscopy survey SDSS-IV MaNGA, including 205 star-forming galaxies in pairs/mergers and ∼1350 control galaxies. For each galaxy in pairs, the merger stage is identified according to its morphological signatures: incoming phase, at first pericenter passage, at apocenter, in merging phase, and in final coalescence. The effect of interactions is quantified by the global and spatially resolved SF rate (SFR) relative to the SFR of a control sample selected for each individual galaxy (Δlog SFR and Δlog sSFR(r), respectively). Analysis of the radial Δlog sSFR(r) distributions shows that galaxy interactions have no significant impact on Δlog sSFR(r) during the incoming phase. Right after the first pericenter passage, the radial Δlog sSFR(r) profile decreases steeply from enhanced to suppressed activity for increasing galactocentric radius. Later on, SF is enhanced on a broad spatial scale out to the maximum radius we explore (∼6.7 kpc) and the enhancement is in general centrally peaked. The extended SF enhancement is also observed for systems at their apocenters and in the coalescence phase, suggesting that interaction-triggered SF is not restricted to the central region of a galaxy. Further explorations of a wide range in parameter space of merger configurations (e.g., mass ratio) are required to constrain the whole picture of interaction-triggered SF.
Abstract
Galactic interactions and subsequent mergers are a paramount channel for galaxy evolution. In this work, we use the data from 236 star-forming CALIFA galaxies with integrated molecular gas ...observations in their central region (approximately within an effective radius)—from the APEX millimeter telescope and the CARMA millimeter telescope array. This sample includes isolated (126 galaxies) and interacting galaxies in different merging stages (110 galaxies; from pairs, merging, and postmerger galaxies). We show that the impact of interactions and mergers in the center of galaxies is revealed as an increase in the fraction of molecular gas (compared to isolated galaxies). Furthermore, our results suggest that the change in star formation efficiency is the main driver for both an enhancement and/or suppression of the central star formation—except in merging galaxies where the enhanced star formation appears to be driven by an increase of molecular gas. We suggest that gravitational torques due to the interaction and subsequent merger transport cold molecular gas inwards, increasing the gas fraction without necessarily increasing star formation.
Abstract
Massive galaxies formed most actively at redshifts
z
= 1–3 during the period known as “cosmic noon.” Here we present an emission-line study of the extremely red quasar ...SDSSJ165202.64+172852.3’s host galaxy at
z
= 2.94, based on observations with the Near Infrared Spectrograph integral field unit on board JWST. We use standard emission-line diagnostic ratios to map the sources of gas ionization across the host and a swarm of companion galaxies. The quasar dominates the photoionization, but we also discover shock-excited regions orthogonal to the ionization cone and the quasar-driven outflow. These shocks could be merger-induced or—more likely, given the presence of a powerful galactic-scale quasar outflow—these are signatures of wide-angle outflows that can reach parts of the galaxy that are not directly illuminated by the quasar. Finally, the kinematically narrow emission associated with the host galaxy presents as a collection of 1 kpc–scale clumps forming stars at a rate of at least 200
M
⊙
yr
−1
. The interstellar medium within these clumps shows high electron densities, reaching up to 3000 cm
−3
, with metallicities ranging from half to a third solar with a positive metallicity gradient, and
V
-band extinctions up to 3 mag. The star formation conditions are far more extreme in these regions than in local star-forming galaxies but consistent with those of massive galaxies at cosmic noon. The JWST observations simultaneously reveal an archetypal rapidly forming massive galaxy undergoing a merger, a clumpy starburst, an episode of obscured near-Eddington quasar activity, and an extremely powerful quasar outflow.
ABSTRACT
We present an empirical relation between the cold gas surface density (Σgas) and the optical extinction (AV) in a sample of 103 galaxies from the Extragalactic Database for Galaxy Evolution ...(EDGE) survey. This survey provides CARMA interferometric CO observations for 126 galaxies included in the Calar Alto Legacy Integral Field Area (CALIFA) survey. The matched, spatially resolved nature of these data sets allows us to derive the Σgas–AV relation on global, radial, and kpc (spaxel) scales. We determine AV from the Balmer decrement (H α/H β). We find that the best fit for this relation is $\Sigma _{\rm gas}\,(\rm {M_\odot \,pc}^{-2}) \sim 26 \times {\rm \mathit{ A}_\mathit{ V}} \,(\rm mag)$, and that it does not depend on the spatial scale used for the fit. However, the scatter in the fits increases as we probe smaller spatial scales, reflecting the complex relative spatial distributions of stars, gas, and dust. We investigate the Σgas/AV ratio on radial and spaxel scales as a function of $\mathrm{EW(H\,\alpha)}$. We find that at larger values of $\mathrm{EW({H\,\alpha })}$ (i.e. actively star-forming regions) this ratio tends to converge to twice the value expected for a foreground dust screen geometry (∼30 $\mathrm{M_{\odot } \, pc^{-2} \, mag^{-1}}$). On radial scales, we do not find a significant relation between the Σgas/AV ratio and the ionized gas metallicity. We contrast our estimates of Σgas using AV with compilations in the literature of the gas fraction on global and radial scales as well as with well-known scaling relations such as the radial star formation law and the Σgas–Σ* relation. These tests show that optical extinction is a reliable proxy for estimating Σgas in the absence of direct sub/millimeter observations of the cold gas.
Abstract
Quasar-driven galactic outflows are a major driver of the evolution of massive galaxies. We report observations of a powerful galactic-scale outflow in a
z
= 3 extremely red and ...intrinsically luminous (
L
bol
≃ 5 × 10
47
erg s
−1
) quasar SDSSJ1652 + 1728 with the Near-infrared Spectrograph on board JWST. We analyze the kinematics of rest-frame optical emission lines and identify the quasar-driven outflow extending out to ∼10 kpc from the quasar with a velocity offset of (
v
r
= ± 500 km s
−1
) and high velocity dispersion (FWHM = 700–2400 km s
−1
). Due to JWST’s unprecedented surface brightness sensitivity in the near-infrared, we unambiguously show that the powerful high velocity outflow in an extremely red quasar encompasses a large swath of the host galaxy’s interstellar medium. Using the kinematics and dynamics of optical emission lines, we estimate the mass outflow rate—in the warm ionized phase alone—to be at least 2300 ± 1400
M
⊙
yr
−1
. We measure a momentum flux ratio between the outflow and the quasar accretion disk of ∼1 on a kpc scale, indicating that the outflow was likely driven in a relatively high (>10
23
cm
−2
) column density environment through radiation pressure on dust grains. We find a coupling efficiency between the bolometric luminosity of the quasar and the outflow of 0.1%, matching the theoretical prediction of the minimum coupling efficiency necessary for negative quasar feedback. The outflow has sufficient energetics to drive the observed turbulence seen in shocked regions of the quasar host galaxy, which are likely directly responsible for prolonging the time that it takes for gas to cool efficiently.
We present 13CO(J = 1 → 0) observations for the EDGE-CALIFA survey, which is a mapping survey of 126 nearby galaxies at a typical spatial resolution of 1.5 kpc. Using detected 12CO emission as a ...prior, we detect 13CO in 41 galaxies via integrated line flux over the entire galaxy and in 30 galaxies via integrated line intensity in resolved synthesized beams. Incorporating our CO observations and optical IFU spectroscopy, we perform a systematic comparison between the line ratio 12/13≡I12CO(J=1→0)/I13CO(J=1→0) and the properties of the stars and ionized gas. Higher 12/13 values are found in interacting galaxies compared to those in noninteracting galaxies. The global 12/13 slightly increases with infrared color F60/F100 but appears insensitive to other host-galaxy properties such as morphology, stellar mass, or galaxy size. We also present azimuthally averaged 12/13 profiles for our sample up to a galactocentric radius of 0.4r25 (∼6 kpc), taking into account the 13CO nondetections by spectral stacking. The radial profiles of 12/13 are quite flat across our sample. Within galactocentric distances of 0.2r25, the azimuthally averaged 12/13 increases with the star formation rate. However, Spearman rank correlation tests show the azimuthally averaged 12/13 does not strongly correlate with any other gas or stellar properties in general, especially beyond 0.2r25 from the galaxy centers. Our findings suggest that in the complex environments in galaxy disks, 12/13 is not a sensitive tracer for ISM properties. Dynamical disturbances, like galaxy interactions or the presence of a bar, also have an overall impact on 12/13, which further complicates the interpretations of 12/13 variations.
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