arXiv subjects

Carlos López Cobá

Publications and source records attributed to Carlos López Cobá.

3 recordsLinked to original sources

arXiv2024

AGN feedback can produce metal enrichment on galaxy scales

Giant (>100 kpc) nebulae associated with active galaxies provide rich information about the circumgalactic medium (CGM) around galaxies, its link with the interstellar medium (ISM) of the hosts and the mechanisms involved in their evolution. We have studied the giant nebula associated with the Teacup (z=0.085) quasar based on VLT MUSE integral field spectroscopy to investigate whether the well known giant (~10 kpc) active galactic nucleus (AGN) induced outflow has an impact on the distribution of heavy elements in and outside the host galaxy. For this, we have mapped the O/H and N/O abundances in two spatial dimensions across the giant nebula and within the galaxy by means of comparing emission line ratios with photoionisation model predictions. We have found that the widely studied AGN driven outflow responsible for the 10 kpc ionised bubble is enhancing the gas metal abundance up to 10 kpc from the AGN. O/H is solar or slightly higher in the bubble edges, in comparison with the subsolar abundances across the rest of the nebula (median O/H~0.63 O/H_sun)). The main conclusion is that AGN feedback can produce metal enrichment at large extranuclear distances in galaxies (>~10 kpc).

astro-ph.GA↗

arXiv2022

Resolved Molecular Gas Observations of MaNGA Post-starbursts Reveal a Tumultuous Past

Post-starburst galaxies (PSBs) have recently and rapidly quenched their star-formation, thus they are an important way to understand how galaxies transition from star-forming late-types to quiescent early-types. The recent discovery of large cold gas reservoirs in PSBs calls into question the theory that galaxies must lose their gas to become quiescent. Optical Integral Field Spectroscopy (IFS) surveys have revealed two classes of PSBs: central PSBs with central quenching regions and ring PSBs with quenching in their outskirts. We analyze a sample of 13 nearby (z < 0.1) PSBs with spatially resolved optical IFS data from the Mapping Nearby Galaxies at Apache Point Observatory (MaNGA) survey and matched resolution Atacama Large (sub-)Millimeter Array (ALMA) observations of $^{12}$CO(1-0). Disturbed stellar kinematics in 7/13 of our PSBs and centrally concentrated molecular gas is consistent with a recent merger for most of our sample. In galaxies without merger evidence, alternate processes may funnel gas inwards and suppress star-formation, which may include outflows, stellar bars, and minor mergers or interactions. The star-formation efficiencies of the post-starburst regions in nearly half our galaxies are suppressed while the gas fractions are consistent with star-forming galaxies. AGN feedback may drive this stabilization, and we observe AGN-consistent emission in the centers of 5/13 galaxies. Finally, our central and ring PSBs have similar properties except the ionized and molecular gas in central PSBs is more disturbed. Overall, the molecular gas in our PSBs tends to be compact and highly disturbed, resulting in concentrated gas reservoirs unable to form stars efficiently.

astro-ph.GA↗

arXiv2022

The ALMaQUEST survey. VIII. What causes the velocity discrepancy between CO and H$α$ rotation curves in galaxies?

We compare the CO(1-0) and H$α$ kinematics in 34 nearby galaxies, selected from the ALMaQUEST and EDGE-CALIFA surveys. We use 3-D Barolo, a 3D tilted ring model, to derive the CO and H$α$ rotation curves. Before comparing rotation curves in the 34 nearby galaxies, we found systematics between the MaNGA and the CALIFA data using eight MaNGA-CALIFA overlapping galaxies. We assume the rotation curves based on the MaNGA data are accurate and made the corresponding correction to the CALIFA data. Our result shows that $\sim$56% (19/34) of our galaxies present slower H$α$ rotation curves compared to the CO rotation curves, with a median value of 6.5 km/s. The remaining galaxies (15/34) show consistent CO-H$α$ rotation velocity within uncertainties. As a result, the Ha rotation may underestimate the total dynamical mass by ~6% for a circular velocity of 200 km/s (the median value in our sample). Furthermore, the velocity difference between the CO and H$α$ rotation velocity is found to correlate with the velocity dispersion difference between CO and H$α$, suggesting that the gas pressure plays a role in the velocity discrepancy. After incorporating the effect of pressure support due to the turbulent gas motion to our sample, the median value of the velocity differences decreases to 1.9 km/s, which in turn reduces the underestimation of dynamical mass to $\sim$2%. Finally, we also investigate the role that the extra-planar diffuse ionized gas (eDIG) plays in the CO-H$α$ velocity discrepancy.

astro-ph.GA↗