Quantifying Feedback from Narrow Line Region Outflows in Nearby Active Galaxies

Observations reveal that supermassive black holes (SMBHs) grow through the accretion of gas at the centers of galaxies as luminous active galactic nuclei (AGN), releasing radiation that drives powerful outflows of ionized and molecular gas. These winds are thought to play a critical role in galaxy evolution by regulating star formation and the growth of galaxies and their SMBHs. To test this model, we must quantify the dynamic impact of outflows by measuring their mass outflow rates and energetics. Using spatially resolved spectroscopy and imaging from the Hubble Space Telescope and Cloudy photoionization models we mapped the ionized gas kinematics and mass distributions of narrow line region (NLR) outflows in nearby active galaxies. We find that the outflows contain up to several million solar masses of ionized gas and are limited to distances of 1 - 2 kiloparsecs from the nucleus. The maximum mass outflow rates are M = 3 - 12 solar masses per year and the outflow gas mass, velocity, radial extent, and energetics are positively correlated with AGN luminosity. We use our results to test simplified techniques with less stringent data requirements and find that they significantly overestimate the gas mass. These results are crucial for modeling powerful outflows at higher redshift that may considerably influence star formation rates and the formation of galactic structure

Interaction of Gravitational Waves with Charged Particles

It is shown here that a cloud of charged particles could in principle absorb energy from gravitational waves (GWs) incident upon it, resulting in wave attenuation. This could in turn have implications for the interpretation of future data from early universe GWs.Comment: Appears in Gravitational Wave Astrophysics, Editor C.F. Sopuerta, Astrophysics and Space Science Proceedings, Volume 40. ISBN 978-3-319-10487-4. Springer International Publishing Switzerland, 2015, p. 29

Jansky Very Large Array detections of CO(1-0) emission in HI-absorption-selected galaxies at z≳2z \gtrsim 2

We report a Karl G. Jansky Very Large Array search for redshifted CO(1-0) emission from three HI-absorption-selected galaxies at $z \approx 2$, identified earlier in their CO(3-2) or CO(4-3) emission. We detect CO(1-0) emission from DLA B1228-113 at $z\approx2.1933$ and DLA J0918+1636 at $z\approx2.5848$; these are the first detections of CO(1-0) emission in high-$z$ HI-selected galaxies. We obtain high molecular gas masses, $\rm M_{mol}\approx10^{11}\times(\alpha_{\rm CO}/4.36)\ M_\odot$, for the two objects with CO(1-0) detections, which are a factor of $\approx1.5-2$ lower than earlier estimates. We determine the excitation of the mid$-J$ CO rotational levels relative to the $J=1$ level, r$_{ J1}$, in HI-selected galaxies for the first time, obtaining r$_{\rm 31}=1.00\pm0.20$ and r$_{\rm 41}=1.03\pm0.23$ for DLA J0918+1636, and r$_{\rm 31}=0.86\pm0.21$ for DLA B1228-113. These values are consistent with thermal excitation of the $J=3,4$ levels. The excitation of the $J=3$ level in the HI-selected galaxies is similar to that seen in massive main-sequence and sub-mm galaxies at $z\gtrsim2$, but higher than that in main-sequence galaxies at $z\approx1.5$; the higher excitation of the galaxies at $z\gtrsim2$ is likely to be due to their higher star-formation rate (SFR) surface density. We use Hubble Space Telescope Wide Field Camera 3 imaging to detect the rest-frame near-ultraviolet emission of DLA B1228-113, obtaining an NUV SFR of $4.44\pm0.47$ M$_{\odot}$ yr$^{-1}$, significantly lower than that obtained from the total infrared luminosity, indicating significant dust extinction in the $z\approx2.1933$ galaxy.Comment: 9 pages, 4 figures, and 2 tables. Accepted for publication in ApJ

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 $\ge$ 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 $\ge$ 5$\sigma$ confidence. In our sample, we measure [NeV]$\lambda$3347, $\lambda$3427, [FeVII]$\lambda$3586, $\lambda$3760, $\lambda$6086, and [FeX]$\lambda$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

Constraints on the densities and temperature of Seyfert 2 NLR

Different studies have reported the so-called temperature problem of the narrow line region (NLR) of active galactic nuclei (AGNs). Its origin is still an open issue. To properly address its cause, a trustworthy temperature indicator is required. We propose that the weak [ArIV] 4711,40A doublet is the appropriate tool for evaluating the density of the high excitation plasma. We subsequently made use of the recent S7 survey sample to extract reliable measurements of the weak [ArIV] doublet in 16 high excitation Seyfert 2s. As a result we could derive the plasma density of the NLR of our Seyfert 2 sample and compare the temperature inferred from the observed [OIII] (4363A/5007A) ratios. It was found that 13 Seyfert 2s cluster near similar values as the [OIII] (4363A/5007A) ratio, at a mean value of 0.0146+-0.0020. Three objects labeled outliers stand out at markedly higher [OIII] values (> 0.03). If for each object one assumes a single density, the values inferred from the [ArIV] doublet for the 13 clustering objects all lie below 60,000 cm-3, indicating that the [OIII] (4363A/5007A) ratios in these objects is a valid tracer of plasma temperature. Even when assuming a continuous power-law distribution of the density, the inferred cut-off density required to reproduce the observed [ArIV] doublet is in all cases < 1E5.1 cm-3. The average NLR temperature inferred for the 13 Seyfert 2s is 13,000+-703 K, which photoionization models have difficulty reproducing. Subsequently we considered different mechanisms to account for the observed [OIII] ratios. For the three outliers, a double-bump density distribution is likely required, with the densest component having a density > 1E6 cm-3.Comment: 21 pages, 9 figures, submitted to A&A, accepted on 4th of Jan 202

The MUSE Ultra Deep Field (MUDF). IV. A pair of X-ray weak quasars at the heart of two extended Ly{\alpha} nebulae

We present the results obtained from follow-up observations of the MUSE Ultra Deep Field (MUDF) at X-ray energies with XMM-Newton. The MUDF is centred on a unique field with two bright, physically associated quasars at $z\simeq3.23$, separated by $\sim$500 kpc in projection. Both quasars are embedded within extended Ly$\alpha$ nebulae ($\gtrsim 100~\rm kpc$ at a surface brightness flux level of $\approx 6\times 10^{-19} \rm erg~s^{-1}~cm^{-2}~arcsec^{-2}$), whose elongated morphology is suggestive of an extended filament connecting the quasar haloes. The new X-ray observations presented here allow us to characterise the physical properties (e.g. X-ray slope, luminosities, gas column densities) in the innermost region of the MUDF quasars. We find that both quasars are X-ray underluminous compared to objects at similar ultraviolet luminosities. Based on our X-ray spectral analysis, absorbing columns of $N_H(z)\gtrsim$ 10$^{23}$ cm$^{-2}$ appear unlikely, therefore such a weakness is possibly intrinsic. When also including literature data, we do not observe any detectable trend between the area of the nebulae and nuclear luminosities at both the rest-frame 2 keV and 2500 $\rm \mathring{A}$. The area is also not correlated with the X-ray photon index nor with the integrated band flux in the hard band (2$-$10 keV). We also do not find any trend between the extended Ly$\alpha$ emission of the nebulae and the nuclear X-ray luminosity. Finally, the properties of the MUDF quasars' nebulae are consistent with the observed relation between the Ly$\alpha$ integrated luminosity of the nebulae and their area. Our results suggest that the quasar ionization power is not a strong driver of the morphology and size of the nebulae.Comment: 15 pages, 9 figures, reference added, published in MNRA