arXiv subjects

Sylvain Veilleux

Publications and source records attributed to Sylvain Veilleux.

At least 73 records · Page 4Linked to original sources

arXiv2022

BASS XXV: DR2 Broad-line Based Black Hole Mass Estimates and Biases from Obscuration

We present measurements of broad emission lines and virial estimates of supermassive black hole masses ($M_{BH}$) for a large sample of ultra-hard X-ray selected active galactic nuclei (AGNs) as part of the second data release of the BAT AGN Spectroscopic Survey (BASS/DR2). Our catalog includes $M_{BH}$ estimates for a total 689 AGNs, determined from the H$α$, H$β$, $MgII\lambda2798$, and/or $CIV\lambda1549$ broad emission lines. The core sample includes a total of 512 AGNs drawn from the 70-month Swift/BAT all-sky catalog. We also provide measurements for 177 additional AGNs that are drawn from deeper Swift/BAT survey data. We study the links between $M_{BH}$ estimates and line-of-sight obscuration measured from X-ray spectral analysis. We find that broad H$α$ emission lines in obscured AGNs ($\log (N_{\rm H}/{\rm cm}^{-2})> 22.0$) are on average a factor of $8.0_{-2.4}^{+4.1}$ weaker, relative to ultra-hard X-ray emission, and about $35_{-12}^{~+7}$\% narrower than in unobscured sources (i.e., $\log (N_{\rm H}/{\rm cm}^{-2}) < 21.5$). This indicates that the innermost part of the broad-line region is preferentially absorbed. Consequently, current single-epoch $M_{BH}$ prescriptions result in severely underestimated ($>$1 dex) masses for Type 1.9 sources (AGNs with broad H$α$ but no broad H$β$) and/or sources with $\log (N_{\rm H}/{\rm cm}^{-2}) > 22.0$. We provide simple multiplicative corrections for the observed luminosity and width of the broad H$α$ component ($L[{\rm b}{\rm H}α]$ and FWHM[bH$α$]) in such sources to account for this effect, and to (partially) remedy $M_{BH}$ estimates for Type 1.9 objects. As key ingredient of BASS/DR2, our work provides the community with the data needed to further study powerful AGNs in the low-redshift Universe.

astro-ph.GA↗

arXiv2022

BASS XXVIII: Near-infrared Data Release 2, High-Ionization and Broad Lines in Active Galactic Nuclei

We present the BAT AGN Spectroscopic Survey (BASS) Near-infrared Data Release 2 (DR2), a study of 168 nearby ($\bar z$ = 0.04, $z$ < 0.6) active galactic nuclei (AGN) from the all-sky Swift Burst Array Telescope X-ray survey observed with Very Large Telescope (VLT)/X-shooter in the near-infrared (NIR; 0.8 - 2.4 $μ$m). We find that 49/109 (45%) Seyfert 2 and 35/58 (60%) Seyfert 1 galaxies observed with VLT/X-shooter show at least one NIR high-ionization coronal line (CL, ionization potential $χ$ > 100 eV). Comparing the emission of the [Si vi] $λ$1.9640 CL with the X-ray emission for the DR2 AGN, we find a significantly tighter correlation, with a lower scatter (0.37 dex) than for the optical [O iii] $λ$5007 line (0.71 dex). We do not find any correlation between CL emission and the X-ray photon index $Γ$. We find a clear trend of line blueshifts with increasing ionization potential in several CLs, such as [Si vi] $λ$1.9640, [Si x] $λ$1.4300, [S viii] $λ$0.9915, and [S ix] $λ$1.2520, indicating the radial structure of the CL region. Finally, we find a strong underestimation bias in black hole mass measurements of Sy 1.9 using broad H$α$ due to the presence of significant dust obscuration. In contrast, the broad Pa$α$ and Pa$β$ emission lines are in agreement with the $M$-$σ$ relation. Based on the combined DR1 and DR2 X-shooter sample, the NIR BASS sample now comprises 266 AGN with rest-frame NIR spectroscopic observations, the largest set assembled to date.

astro-ph.GA↗

arXiv2022

BASS XXII: The BASS DR2 AGN Catalog and Data

We present the AGN catalog and optical spectroscopy for the second data release of the Swift BAT AGN Spectroscopic Survey (BASS DR2). With this DR2 release we provide 1425 optical spectra, of which 1181 are released for the first time, for the 858 hard X-ray selected AGN in the Swift BAT 70-month sample. The majority of the spectra (813/1425, 57%) are newly obtained from VLT/Xshooter or Palomar/Doublespec. Many of the spectra have both higher resolution (R>2500, N~450) and/or very wide wavelength coverage (3200-10000 A, N~600) that are important for a variety of AGN and host galaxy studies. We include newly revised AGN counterparts for the full sample and review important issues for population studies, with 44 AGN redshifts determined for the first time and 780 black hole mass and accretion rate estimates. This release is spectroscopically complete for all AGN (100%, 858/858) with 99.8% having redshift measurements (857/858) and 96% completion in black hole mass estimates of unbeamed AGN (outside the Galactic plane). This AGN sample represents a unique census of the brightest hard X-ray selected AGN in the sky, spanning many orders of magnitude in Eddington ratio (Ledd=10^-5-100), black hole mass (MBH=10^5-10^10 Msun), and AGN bolometric luminosity (Lbol=10^40-10^47 ergs/s).

astro-ph.GA↗

arXiv2022

The Morpho-Kinematic Architecture of Super Star Clusters in the Center of NGC253

The center of the nearby galaxy NGC\,253 hosts a population of more than a dozen super star clusters (SSCs) which are still in the process of forming. The majority of the star formation of the burst is concentrated in these SSCs, and the starburst is powering a multiphase outflow from the galaxy. In this work, we measure the 350~GHz dust continuum emission towards the center of NGC\,253 at 47~milliarcsecond (0.8 pc) resolution using data from the Atacama Large Millimeter/submillimeter Array (ALMA). We report the detection of 350~GHz (dust) continuum emission in the outflow for the first time, associated with the prominent South-West streamer. In this feature, the dust emission has a width of $\approx$~8~pc, is located at the outer edge of the CO emission, and corresponds to a molecular gas mass of $\sim~(8-17)\times10^6$~M$_\odot$. In the starburst nucleus, we measure the resolved radial profiles, sizes, and molecular gas masses of the SSCs. Compared to previous work at somewhat lower spatial resolution, the SSCs here break apart into smaller substructures with radii $0.4-0.7$~pc. In projection, the SSCs, dust, and dense molecular gas appear to be arranged as a thin, almost linear, structure roughly 155~pc in length. The morphology and kinematics of this structure can be well explained as gas following $x_2$ orbits at the center of a barred potential. We constrain the morpho-kinematic arrangement of the SSCs themselves, finding that an elliptical, angular momentum-conserving ring is a good description of the both morphology and kinematics of the SSCs.

astro-ph.GA↗

arXiv2022

Galactic Winds across the Gas-Rich Merger Sequence II. Lyman Alpha Emission and Highly Ionized O VI and N V Outflows in Ultraluminous Infrared Galaxies

This paper is the second in a series aimed at examining the gaseous environments of z$\le$0.3 quasars and ultraluminous infrared galaxies (ULIRGs) as a function of AGN/host galaxy properties across the merger sequence. This second paper focuses on the Ly$α$ emission and O VI and N V absorption features, tracers of highly ionized gas outflows, in ULIRGs observed with HST/COS. Ly$α$ emission is detected in 15 out of 19 ULIRGs, and 12 of the 14 clear Ly$α$ detections show emission with blueshifted velocity centroids and/or wings. The equivalent widths of the Ly$α$ emission increase with increasing AGN luminosities and AGN bolometric fractions. The blueshifts of the Ly$α$ emission correlate positively with those of the [O III] emission, where the latter traces the ionized gas outflows. The Ly$α$ escape fractions tend to be slightly larger in objects with stronger AGN and larger outflow velocities, but they do not correlate with nebular line reddening. Among the 12 ULIRGs with good continuum signal-to-noise ratios, O VI and/or N V absorption features are robustly detected in 6 of them, all of which are blueshifted, indicative of outflows. In the combined ULIRG $+$ quasar sample, the outflows are more frequently detected in the X-ray weak or absorbed sources. The absorption equivalent widths, velocities and velocity dispersions of the outflows are also higher in the X-ray weak sources. No other strong correlations are visible between the properties of the outflows and those of the AGN or host galaxies.

astro-ph.GA↗

arXiv2022

On-Chip High Extinction Ratio Single-Stage Mach-Zehnder Interferometer based on Multimode Interferometer

On-chip high extinction ratio Mach-Zehnder interferometers (MZI) have always attracted interest from researchers as it can be used in many applications in astrophotonics, optical switching, programmable photonic circuits, and quantum information. However, in previous research studies, ultra-high extinction ratio on-chip MZIs have only been achieved by using a multi-stage MZI approach. In this paper, we investigate a high extinction ratio single-stage MZI based on two cascaded multimode interferometers (MMI). We determine that TM noise is an important factor that can prevent us from achieving a high extinction ratio MZI. By introducing a bend-based TM filter without additional loss, we experimentally demonstrate that such a TM filter can improve the maximum extinction ratio of the MMI-MZI by more than 10 dB. With the TM filter, we report a record high 61.2 dB extinction ratio in a single stage, thermally tunable MMI-MZI with only 1.5 dB insertion loss and more than 60nm bandwidth. These results pave the way for many interesting applications.

physics.optics↗

arXiv2022

Development of an integrated near-IR astrophotonic spectrograph

Here, we present an astrophotonic spectrograph in the near-IR H-band (1.45 -1.65 $μm$) and a spectral resolution ($λ/δλ$) of 1500. The main dispersing element of the spectrograph is a photonic chip based on Arrayed-Waveguide-Grating technology. The 1D spectrum produced on the focal plane of the AWG contains overlapping spectral orders, each spanning a 10 nm band in wavelength. These spectral orders are cross-dispersed in the perpendicular direction using a cross-dispersion setup which consists of collimating lenses and a prism and the 2D spectrum is thus imaged onto a near-IR detector. Here, as a proof of concept, we use a few-mode photonic lantern to capture the light and feed the emanating single-mode outputs to the AWG chip for dispersion. The total size of the setup is 50$\times$30$\times$20 cm$^3$, nearly the size of a shoebox. This spectrograph will pave the way for future miniaturized integrated photonic spectrographs on large telescopes, particularly for building future photonic multi-object spectrographs.

astro-ph.IM↗

arXiv2022

The CGM-GRB Study II: Outflow-Galaxy Connection at z ~ 2-6

We use a sample of 27 GRBs at redshift $z=2-6$ to probe the outflows in their respective host galaxies ($\mathrm{log(M_*/M_{\odot})}~\sim~9-11$) and search for possible relations between the outflow properties and those of the host galaxies such as $\mathrm{M_*}$, SFR, and specific SFR. First, we consider three outflow properties $-$ outflow column density ($\mathrm{N_{out}}$), maximum outflow velocity ($\mathrm{V_{max}}$), and normalized maximum velocity ($\mathrm{V_{norm}}$ = $\mathrm{V_{max}/V_{circ, halo}}$, where $\mathrm{V_{circ,halo}}$ is the halo circular velocity). We observe clear trends of $\mathrm{N_{out}}$ and $\mathrm{V_{max}}$ with increasing SFR in high-ion-traced outflows, with a stronger ($>~3σ$) $\mathrm{V_{max}}-$SFR correlation. We find that the estimated mass outflow rate and momentum flux of the high-ion outflows scale with SFR and can be supported by the momentum imparted by star formation (supernovae and stellar winds). The kinematic correlations of high-ion-traced outflows with SFR are similar to those observed for star-forming galaxies at low redshifts. The correlations with SFR are weaker in low-ions. This, along with the lower detection fraction in low-ions, indicates that the outflow is primarily high-ion dominated. We also observe a strong ($>~3σ$) trend of normalized velocity ($\mathrm{V_{norm}}$) decreasing with halo mass and increasing with sSFR, suggesting that outflows from low-mass halos and high-sSFR galaxies are most likely to escape and enrich the outer CGM and IGM with metals. By comparing the CGM-GRB stacks with those of starbursts at $z\sim2$ and $z\sim0.1$, we find that over a broad redshift range, the outflow strength strongly depends on the main-sequence offset at the respective redshifts rather than simply the SFR.

astro-ph.GA↗

arXiv2021

Galactic Winds across the Gas-Rich Merger Sequence: I. Highly Ionized N V and O VI Outflows in the QUEST Quasars

This program is part of QUEST (Quasar/ULIRG Evolutionary Study) and seeks to examine the gaseous environments of z < 0.3 quasars and ULIRGs as a function of host galaxy properties and age across the merger sequence from ULIRGs to quasars. This first paper in the series focuses on 33 quasars from the QUEST sample and on the kinematics of the highly ionized gas phase traced by the N V 1238, 1243 A and O VI 1032, 1038 A absorption lines in high-quality Hubble Space Telescope (HST) Cosmic Origins Spectrograph (COS) data. N V and O VI outflows are present in about 60% of the QUEST quasars and span a broad range of properties, both in terms of equivalent widths (from 20 mA to 25 A) and kinematics (outflow velocities from a few x 100 km/s up to ~10,000 km/s). The rate of incidence and equivalent widths of the highly ionized outflows are higher among X-ray weak or absorbed sources. The weighted outflow velocity dispersions are highest among the X-ray weakest sources. No significant trends are found between the weighted outflow velocities and the properties of the quasars and host galaxies although this may be due to the limited dynamic range of properties of the current sample. These results will be re-examined in an upcoming paper where the sample is expanded to include the QUEST ULIRGs. Finally, a lower limit of ~0.1% on the ratio of time-averaged kinetic power to bolometric luminosity is estimated in the 2-4 objects with blueshifted P V 1117, 1128 absorption features.

astro-ph.GA↗

arXiv2021

ALMA Imaging of a Galactic Molecular Outflow in NGC4945

We present the ALMA detection of molecular outflowing gas in the central regions of NGC4945, one of the nearest starbursts and also one of the nearest hosts of an active galactic nucleus (AGN). We detect four outflow plumes in CO (3-2) at ~0.3" resolution that appear to correspond to molecular gas located near the edges of the known ionized outflow cone and its (unobserved) counterpart behind the disk. The fastest and brightest of these plumes has emission reaching observed line-of-sight projected velocities of over 450 km/s beyond systemic, equivalent to an estimated physical outflow velocity v>600 km/s for the fastest emission. Most of these plumes have corresponding emission in HCN or HCO+ (4-3). We discuss a kinematic model for the outflow emission where the molecular gas has the geometry of the ionized gas cone and shares the rotation velocity of the galaxy when ejected. We use this model to explain the velocities we observe, constrain the physical speed of the ejected material, and account for the fraction of outflowing gas that is not detected due to confusion with the galaxy disk. We estimate a total molecular mass outflow rate dMmol/dt~20 Msun/yr flowing through a surface within 100 pc of the disk midplane, likely driven by a combination of the central starburst and AGN.

astro-ph.GA↗

arXiv2021

Probing the circumnuclear environment of NGC1275 with High-Resolution X-ray spectroscopy

NGC1275 is the Brightest Cluster Galaxy (BCG) in the Perseus cluster and hosts the active galactic nucleus (AGN) that is heating the central 100\,kpc of the intracluster medium (ICM) atmosphere via a regulated feedback loop. Here we use a deep 490ks Cycle-19 Chandra High-Energy Transmission Grating (HETG) observation of NGC1275 to study the anatomy of this AGN. The X-ray continuum is adequately described by an unabsorbed power-law with photon index $Γ\approx 1.9$, creating strong tension with the detected column of molecular gas seen via HCN and HCO$^+$ line absorption against the parsec-scale core/jet. This tension is resolved if we permit a composite X-ray source; allowing a column of $N_H\sim 8\times 10^{22}\,{\rm cm}^{-2}$ to cover $\sim 15$% of the X-ray emitter does produce a significant improvement in the statistical quality of the spectral fit. We suggest that the dominant unabsorbed component corresponds to the accretion disk corona, and the sub-dominant X-ray component is the jet working surface and/or jet cocoon that is expanding into clumpy molecular gas. We suggest that this may be a common occurence in BCG-AGN. We conduct a search for photoionized absorbers/winds and fail to detect such a component, ruling out columns and ionization parameters often seen in many other Seyfert galaxies. We detect the 6.4keV iron-K$α$ fluorescence line seen previously by XMM-Newton and Hitomi. We describe an analysis methodology which combines dispersive HETG spectra, non-dispersive microcalorimeter spectra, and sensitive XMM-Newton/EPIC spectra in order to constrain (sub)arcsec-scale extensions of the iron-K$α$ emission region.

astro-ph.HE↗

arXiv2021

Powerful winds in high-redshift obscured and red quasars

Quasar-driven outflows must have made their most significant impact on galaxy formation during the epoch when massive galaxies were forming most rapidly. To study the impact of quasar feedback we conducted rest-frame optical integral field spectrograph (IFS) observations of three extremely red quasars (ERQs) and one type-2 quasar at $z=2-3$, obtained with the NIFS and OSIRIS instruments at the Gemini North and W. M. Keck Observatory with the assistance of laser-guided adaptive optics. We use the kinematics and morphologies of the [OIII] 5007Åand H$α$ 6563Åemission lines redshifted into the near-infrared to gauge the extents, kinetic energies and momentum fluxes of the ionized outflows in the quasars host galaxies. For the ERQs, the galactic-scale outflows are likely driven by radiation pressure in a high column density environment or due to an adiabatic shock. For the type-2 quasar, the outflow is driven by radiation pressure in a low column density environment or due to a radiative shock. The outflows in the ERQs carry a significant amount of energy ranging from 0.05-5$\%$ of the quasar's bolometric luminosity, powerful enough to have a significant impact on the quasar host galaxies. However, the outflows are likely only impacting the inner few kpc of each host galaxy. The observed outflow sizes are generally smaller than other ionized outflows observed at high redshift. The high ratio between the momentum flux of the ionized outflow and the photon momentum flux from the quasar accretion disk and high nuclear obscuration makes these ERQs great candidates for transitional objects where the outflows are likely responsible for clearing material in the inner regions of each galaxy, unveiling the quasar accretion disk at optical wavelengths.

astro-ph.GA↗

arXiv2021

NOEMA High Fidelity Imaging of the Molecular Gas in and around M82

We present a 154 pointing IRAM NOEMA mosaic of the CO(1-0) line emission in and around the nearby starburst galaxy M82. The observations, complemented by zero--spacing observations, reach a spatial resolution of $\sim$30 pc ($\sim 1.9^{\prime\prime}$) at 5.0 km s$^{-1}$ spectral resolution, sufficient to resolve the molecular gas in the central starburst disk, the outflow, as well as the tidal streamers. The resulting moment and peak brightness maps show a striking amount of structure. Using a clump decomposition algorithm, we analyse the physical properties (e.g., radii $R$, line widths $σ$, and masses $M$) of $\sim2000$ molecular clouds. To first order, the clouds' properties are very similar, irrespective of their environment. This also holds for the size-line width relations of the clouds. The distribution of clouds in the $σ^2/R$ vs. column density $Σ$ space suggests that external pressure does not play a significant role in setting their physical parameters in the outflow and the streamers. We find that the clouds in the streamers stay approximately constant in size ($R \sim 50$ pc) and mass ($M \sim 10^5$ M$_\odot$) and do not vary with their projected distance from M82's center. The clouds in the outflow, on the other hand, appear to decrease in size and mass with distance towards the Southern outflow. The reduction in the molecular gas luminosity could be indicative of cloud evaporation of embedded clouds in the hot outflow.

astro-ph.GA↗

arXiv2021

Outflows from Super Star Clusters in the Central Starburst of NGC253

Young massive clusters play an important role in the evolution of their host galaxies, and feedback from the high-mass stars in these clusters can have profound effects on the surrounding interstellar medium. The nuclear starburst in the nearby galaxy NGC253 at a distance of 3.5 Mpc is a key laboratory in which to study star formation in an extreme environment. Previous high resolution (1.9 pc) dust continuum observations from ALMA discovered 14 compact, massive super star clusters (SSCs) still in formation. We present here ALMA data at 350 GHz with 28 milliarcsecond (0.5 pc) resolution. We detect blueshifted absorption and redshifted emission (P-Cygni profiles) towards three of these SSCs in multiple lines, including CS 7$-$6 and H$^{13}$CN 4$-$3, which represents direct evidence for previously unobserved outflows. The mass contained in these outflows is a significant fraction of the cluster gas masses, which suggests we are witnessing a short but important phase. Further evidence of this is the finding of a molecular shell around the only SSC visible at near-IR wavelengths. We model the P-Cygni line profiles to constrain the outflow geometry, finding that the outflows must be nearly spherical. Through a comparison of the outflow properties with predictions from simulations, we find that none of the available mechanisms completely explains the observations, although dust-reprocessed radiation pressure and O star stellar winds are the most likely candidates. The observed outflows will have a very substantial effect on the clusters' evolution and star formation efficiency.

astro-ph.GA↗

arXiv2021

Near-Infrared Coronal Line Observations of Dwarf Galaxies hosting AGN-driven Outflows

We have obtained Keck NIR spectroscopy of a sample of nine M$_\star$ $<$ 10$^{10}$ M$_\odot$ dwarf galaxies to confirm AGN activity and the presence of galaxy-wide, AGN-driven outflows through coronal line (CL) emission. We find strong CL detections in 5/9 galaxies (55$\%$) with line ratios incompatible with shocks, confirming the presence of AGN in these galaxies. Similar CL detection rates are found in larger samples of more massive galaxies hosting type 1 and 2 AGN. We investigate the connection between the CLs and galaxy-wide outflows by analyzing the kinematics of the CL region, as well as the scaling of gas velocity with ionization potential of different CLs. In addition, using complementary Keck KCWI observations of these objects, we find that the outflow velocities measured in [Si VI] are generally faster than those seen in [O III]. The galaxies with the fastest outflows seen in [O III] also have the highest [Si VI] luminosity. The lack of $J$-band CN absorption features, which are often associated with younger stellar populations, provides further evidence that these outflows are driven by AGN in low mass galaxies.

astro-ph.GA↗

arXiv2021

X-ray analysis of SDSS J165202.60+172852.4, an obscured quasar with outflows at peak galaxy formation epoch

We report on deep XMM-Newton and NuSTAR observations of the high redshift, z=2.94, extremely red quasar (ERQ), SDSS J165202.60+172852.4, with known galactic ionized outflows detected via spatially-resolved [OIII] emission lines. X-ray observations allow us to directly probe the accretion disk luminosity and the geometry and scale of the circumnuclear obscuration. We fit the spectra from the XMM-Newton/EPIC and NuSTAR detectors with a physically motivated torus model and constrain the source to exhibit a near Compton-thick column density of $N_H=(1.02^{+0.76}_{-0.41})\times10^{24}\textrm{ cm}^{-2}$, a near edge-on geometry with the line-of-sight inclination angle of $θ_i=85^{\circ}$, and a scattering fraction of $f_{sc}\sim 3$ %. The absorption-corrected, intrinsic 2-10 keV X-ray luminosity of $L_{\textrm{2-10}}=(1.4^{+1}_{-1}) \times10^{45} \textrm{ erg s}^{-1}$ reveals a powerful quasar that is not intrinsically X-ray weak, consistent with observed trends in other ERQs. We also estimate the physical properties of the obscuration, although highly uncertain: the warm ionized scattering density of $n_e \sim 7.5\times(10^2-10^3)\textrm{ cm}^{-3}$ and the obscuration mass of $M_{obsc} \sim 1.7\times(10^4-10^6) M_{\odot}$. As previously suggested with shallower X-ray observations, optical and infrared selection of ERQ has proved effective in finding obscured quasars with powerful outflow signatures. Our observations provide an in-depth view into the X-ray properties of ERQs and support the conclusions of severely photon-limited studies of obscured quasar populations at high redshifts.

astro-ph.GA↗

arXiv2020

Astrophysical limits on very light axion-like particles from Chandra grating spectroscopy of NGC 1275

Axions/axion-like particles (ALPs) are a well motivated extension of the Standard Model and are generic within String Theory. The X-ray transparency of the intracluster medium (ICM) in galaxy clusters is a powerful probe of light ALPs (with mass $<10^{-11}\,{\rm eV}$); as X-ray photons from an embedded or background source propagate through the magnetized ICM, they may undergo energy-dependent quantum mechanical conversion into ALPs (and vice versa), imprinting distortions on the X-ray spectrum. We present Chandra data for the active galactic nucleus NGC1275 at the center of the Perseus cluster. Employing a 490ks High-Energy Transmission Gratings (HETG) exposure, we obtain a high-quality 1-9keV spectrum free from photon pileup and ICM contamination. Apart from iron-band features, the spectrum is described by a power-law continuum, with any spectral distortions at the $<3\%$ level. We compute photon survival probabilities as a function of ALP mass $m_a$ and ALP-photon coupling constant $g_{aγ}$ for an ensemble of ICM magnetic field models, and then use the NGC1275 spectrum to constraint the $(m_a, g_{aγ})$-plane. Marginalizing over magnetic field realizations, the 99.7% credible region limits the ALP-photon coupling to $g_{aγ}<6-8\times 10^{-13}\, {\rm GeV}^{-1}$ (depending upon magnetic field model) for masses $m_a<1\times 10^{-12}\,{\rm eV}$. These are the most stringent limit to date on $g_{aγ}$ for these light ALPs, and have already reached the sensitivity limits of next-generation helioscopes and light-shining-through-wall experiments. We highlight the potential of these studies with the next-generation X-ray observatories Athena and Lynx, but note the critical importance of advances in relative calibration of these future X-ray spectrometers.

hep-ph↗

arXiv2020

Ionized outflows from active galactic nuclei as the essential elements of feedback

Outflows from active galactic nuclei (AGN) are one of the fundamental mechanisms by which the central supermassive black hole interacts with its host galaxy. Detected in $\ge 50\%$ of nearby AGN, these outflows have been found to carry kinetic energy that is a significant fraction of AGN power, and thereby give negative feedback to their host galaxies. To understand the physical processes that regulate them, it is important to have a robust estimate of their physical and dynamical parameters. In this review we summarize our current understanding on the physics of the ionized outflows detected in absorption in the UV and X-ray wavelength bands. We discuss the most relevant observations and our current knowledge and uncertainties in the measurements of the outflow parameters. We also discuss their origin and acceleration mechanisms. The commissioning and concept studies of large telescope missions with high resolution spectrographs in UV/optical and X-rays along with rapid advancements in simulations offer great promise for discoveries in this field over the next decade.

astro-ph.GA↗