arXiv subjects

Richard Mushotzky

Publications and source records attributed to Richard Mushotzky.

At least 91 records · Page 5Linked to original sources

arXiv2018

The 105 month Swift-BAT all-sky hard X-ray survey

We present a catalog of hard X-ray sources detected in the first 105 months of observations with the Burst Alert Telescope (BAT) coded mask imager on board the Swift observatory. The 105 month Swift-BAT survey is a uniform hard X-ray all-sky survey with a sensitivity of $8.40\times 10^{-12}\ {\rm erg\ s^{-1}\ cm^{-2}}$ over 90% of the sky and $7.24\times 10^{-12}\ {\rm erg\ s^{-1}\ cm^{-2}}$ over 50% of the sky in the 14-195 keV band. The Swift-BAT 105 month catalog provides 1632 (422 new detections) hard X-ray sources in the 14-195 keV band above the 4.8σ significance level. Adding to the previously known hard X-ray sources, 34% (144/422) of the new detections are identified as Seyfert AGN in nearby galaxies (z<0.2). The majority of the remaining identified sources are X-ray binaries (7%, 31) and blazars/BL Lac objects (10%, 43). As part of this new edition of the Swift-BAT catalog, we release eight-channel spectra and monthly sampled light curves for each object in the online journal and at the Swift-BAT 105 month Web site.

astro-ph.HE↗

arXiv2017

The close environments of accreting massive black holes are shaped by radiative feedback

The large majority of the accreting supermassive black holes in the Universe are obscured by large columns of gas and dust. The location and evolution of this obscuring material have been the subject of intense research in the past decades, and are still highly debated. A decrease in the covering factor of the circumnuclear material with increasing accretion rates has been found by studies carried out across the electromagnetic spectrum. The origin of this trend has been suggested to be driven either by the increase in the inner radius of the obscuring material with incident luminosity due to the sublimation of dust; by the gravitational potential of the black hole; by radiative feedback; or by the interplay between outflows and inflows. However, the lack of a large, unbiased and complete sample of accreting black holes, with reliable information on gas column density, luminosity and mass, has left the main physical mechanism regulating obscuration unclear. Using a systematic multi-wavelength survey of hard X-ray-selected black holes, here we show that radiation pressure on dusty gas is indeed the main physical mechanism regulating the distribution of the circumnuclear material. Our results imply that the bulk of the obscuring dust and gas in these objects is located within the sphere of influence of the black hole (i.e., a few to tens of parsecs), and that it can be swept away even at low radiative output rates. The main physical driver of the differences between obscured and unobscured accreting black holes is therefore their mass-normalized accretion rate.

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arXiv2017

BAT AGN Spectroscopic Survey I: Spectral Measurements, Derived Quantities, and AGN Demographics

We present the first catalog and data release of the Swift-BAT AGN Spectroscopic Survey (BASS). We analyze optical spectra of the majority of AGN (77%, 641/836) detected based on their 14-195 keV emission in the 70-month Swift BAT all-sky catalog. This includes redshift determination, absorption and emission line measurements, and black hole mass and accretion rate estimates for the majority of obscured and un-obscured AGN (74%, 473/641) with 340 measured for the first time. With ~90% of sources at z<0.2, the survey represents a significant census of hard-X-ray selected AGN in the local universe. In this first catalog paper, we describe the spectroscopic observations and datasets, and our initial spectral analysis. The FWHM of the emission lines show broad agreement with the X-ray obscuration (~94%), such that Sy 1-1.8 have NH<10^21.9 cm^-2, and Seyfert 2, have NH>10^21.9 cm^-2. Seyfert 1.9 show a range of column densities. Compared to narrow line AGN in the SDSS, the X-ray selected AGN have a larger fraction of dusty host galaxies suggesting these types of AGN are missed in optical surveys. Using the most sensitive [OIII]/Hbeta and [NII]/Halpha emission line diagnostic, about half of the sources are classified as Seyferts, ~15% reside in dusty galaxies that lack an Hbeta detection, but for which the line upper limits imply either a Seyfert or LINER, ~15% are in galaxies with weak or no emission lines despite high quality spectra, and a few percent each are LINERS, composite galaxies, HII regions, or in known beamed AGN.

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arXiv2017

The Swift/BAT AGN Spectroscopic Survey (BASS) -- VI. The Gamma_X - L/L_Edd relation

We study the observed relation between accretion rate (in terms of L/L_Edd) and shape of the hard X-ray spectral energy distribution (namely the photon index Gamma_X) for a large sample of 228 hard X-ray selected, low-redshift active galactic nuclei (AGN), drawn from the Swift/BAT AGN Spectroscopic Survey (BASS). This includes 30 AGN for which black hole mass (and therefore L/L_Edd) is measured directly through masers, spatially resolved gas or stellar dynamics, or reverberation mapping. The high quality and broad energy coverage of the data provided through BASS allow us to examine several alternative determinations of both Gamma_X and L/L_Edd. For the BASS sample as a whole, we find a statistically significant, albeit very weak correlation between Gamma_X and L/L_Edd. The best-fitting relations we find, Gamma_X=0.15 log(L/L_Edd)+const., are considerably shallower than those reported in previous studies. Moreover, we find no corresponding correlations among the subsets of AGN with different M_BH determination methodology. In particular, we find no robust evidence for a correlation when considering only those AGN with direct or single-epoch M_BH estimates. This latter finding is in contrast to several previous studies which focused on z>0.5 broad-line AGN. We discuss this tension and conclude that it can be partially accounted for if one adopts a simplified, power-law X-ray spectral model, combined with L/L_Edd estimates that are based on the continuum emission and on single-epoch broad line spectroscopy in the optical regime. We finally highlight the limitations on using Gamma_X as a probe of supermassive black hole evolution in deep extragalactic X-ray surveys.

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arXiv2017

BAT AGN Spectroscopic Survey - IV: Near-Infrared Coronal Lines, Hidden Broad Lines, and Correlation with Hard X-ray Emission

We provide a comprehensive census of the near-Infrared (NIR, 0.8-2.4 $μ$m) spectroscopic properties of 102 nearby (z < 0.075) active galactic nuclei (AGN), selected in the hard X-ray band (14-195 keV) from the Swift-Burst Alert Telescope (BAT) survey. With the launch of the James Webb Space Telescope this regime is of increasing importance for dusty and obscured AGN surveys. We measure black hole masses in 68% (69/102) of the sample using broad emission lines (34/102) and/or the velocity dispersion of the Ca II triplet or the CO band-heads (46/102). We find that emission line diagnostics in the NIR are ineffective at identifying bright, nearby AGN galaxies because ([Fe II] 1.257$μ$m/Pa$β$ and H$_2$ 2.12$μ$m/Br$γ$) identify only 25% (25/102) as AGN with significant overlap with star forming galaxies and only 20% of Seyfert 2 have detected coronal lines (6/30). We measure the coronal line emission in Seyfert 2 to be weaker than in Seyfert 1 of the same bolometric luminosity suggesting obscuration by the nuclear torus. We find that the correlation between the hard X-ray and the [Si VI] coronal line luminosity is significantly better than with the [O III] luminosity. Finally, we find 3/29 galaxies (10%) that are optically classified as Seyfert 2 show broad emission lines in the NIR. These AGN have the lowest levels of obscuration among the Seyfert 2s in our sample ($\log N_{\rm H} < 22.43$ cm$^{-2}$), and all show signs of galaxy-scale interactions or mergers suggesting that the optical broad emission lines are obscured by host galaxy dust.

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arXiv2016

BAT AGN Spectroscopic Survey-III. An observed link between AGN Eddington ratio and narrow emission line ratios

We investigate the observed relationship between black hole mass ($M_{\rm BH}$), bolometric luminosity ($L_{\rm bol}$), and Eddington ratio ($λ_{\rm Edd}$) with optical emission line ratios ([NII] λ6583/Hα, [SII] λλ6716,6731/Hα, [OI] λ6300/Hα, [OIII] λ5007/Hβ, [NeIII] λ3869/Hβ, and HeII λ4686/Hβ) of hard X-ray-selected AGN from the BAT AGN Spectroscopic Survey (BASS). We show that the [NII] λ6583/Hα ratio exhibits a significant correlation with $λ_{\rm Edd}$ ($R_{\rm Pear}$ = -0.44, $p$-value=$3\times10^{-13}$, σ = 0.28 dex), and the correlation is not solely driven by $M_{\rm BH}$ or $L_{\rm bol}$. The observed correlation between [NII] λ6583/Hα ratio and $M_{\rm BH}$ is stronger than the correlation with $L_{\rm bol}$, but both are weaker than the $λ_{\rm Edd}$ correlation. This implies that the large-scale narrow lines of AGN host galaxies carry information about the accretion state of the AGN central engine. We propose that the [NII] λ6583/Hα is a useful indicator of Eddington ratio with 0.6 dex of rms scatter, and that it can be used to measure $λ_{\rm Edd}$ and thus $M_{\rm BH}$ from the measured $L_{\rm bol}$, even for high redshift obscured AGN. We briefly discuss possible physical mechanisms behind this correlation, such as the mass-metallicity relation, X-ray heating, and radiatively driven outflows.

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arXiv2016

Study of Swift/BAT Selected Low-luminosity Active Galactic Nuclei Observed with Suzaku

We systematically analyze the broadband (0.5--200 keV) X-ray spectra of hard X-ray ($>10$ keV) selected local low-luminosity active galactic nuclei (LLAGNs) observed with {\it Suzaku} and {\it Swift}/BAT. The sample consists of ten LLAGNs detected with {\it Swift}/BAT with intrinsic 14--195 keV luminosities smaller than $10^{42}$ erg s$^{-1}$ available in the {\it Suzaku} archive, covering a wide range of the Eddington ratio from $10^{-5}$ to $10^{-2}$. The overall spectra can be reproduced with an absorbed cut-off power law, often accompanied by reflection components from distant cold matter, and/or optically-thin thermal emission from the host galaxy. In all objects, relativistic reflection components from the innermost disk are not required. Eight objects show a significant narrow iron-K$α$ emission line. Comparing their observed equivalent widths with the predictions from the Monte-Carlo based torus model by \cite{Ike09}, we constrain the column density in the equatorial plane to be $\log N^{\rm eq}_{\rm H} > 22.7$ or the torus half opening angle $θ_{\rm oa} < 70^\circ$. We infer that the Eddington ratio ($λ_{\rm Edd}$) is a key parameter that determines the torus structure of LLAGNs: the torus becomes large at $λ_{\rm Edd} \gtrsim 2\times10^{-4}$, whereas at lower accretion rates it is little developed. The luminosity correlation between the hard X-ray and mid-infrared (MIR) bands of the LLAGNs follows the same one as for more luminous AGNs. This implies that other mechanisms than AGN-heated dust are responsible for the MIR emission in low Eddington ratio LLAGNs.

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arXiv2015

Flows of X-ray gas reveal the disruption of a star by a massive black hole

Tidal forces close to massive black holes can violently disrupt stars that make a close approach. These extreme events are discovered via bright X-ray and optical/UV flares in galactic centers. Prior studies based on modeling decaying flux trends have been able to estimate broad properties, such as the mass accretion rate. Here we report the detection of flows of highly ionized X-ray gas in high-resolution X-ray spectra of a nearby tidal disruption event. Variability within the absorption-dominated spectra indicates that the gas is relatively close to the black hole. Narrow line widths indicate that the gas does not stretch over a large range of radii, giving a low volume filling factor. Modest outflow speeds of a few hundred kilometers per second are observed, significantly below the escape speed from the radius set by variability. The gas flow is consistent with a rotating wind from the inner, super-Eddington region of a nascent accretion disk, or with a filament of disrupted stellar gas near to the apocenter of an elliptical orbit. Flows of this sort are predicted by fundamental analytical theory and more recent numerical simulations.

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arXiv2015

BAT AGN Spectroscopic Survey II: X-ray Emission and High Ionization Optical Emission Lines

We investigate the relationship between X-ray and optical line emission in 340 nearby AGN selected above 10 keV using Swift BAT. We find a weak correlation between the extinction corrected [O III] and hard X-ray luminosity (14-195 keV) with a [OIII] large scatter (R_Pear = 0.64, sigma = 0.62 dex) and a similarly large scatter with the intrinsic 2-10 keV to [O III] luminosities (RPear=0.63, sigma = 0.63 dex). Correlations of the hard X-ray fluxes with the fluxes of high-ionization narrow lines ([O III], He II, [Ne III] and [Ne V]) are not significantly better than with the low ionization lines (Halpha, [SII]). Factors like obscuration or physical slit size are not found to be a significant part of the large scatter. In contrast, the optical emission lines show much better correlations with each other (sigma = 0.3 dex) than with the X-ray flux. The inherent large scatter questions the common usage of narrow emission lines as AGN bolometric luminosity indicators and suggests that other issues such as geometrical differences in the scattering of the ionized gas or long term AGN variability are important.

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arXiv2015

Active Galactic Nuclei Discovered in the Kepler Mission

We report on candidate active galactic nuclei (AGN) discovered during the monitoring of $\sim$500 bright (r < 18 mag) galaxies over several years with the Kepler Mission. Most of the targets were sampled every 30 minutes nearly continuously for a year or more. Variations of 0.001 mag and often less could be detected reliably. About 4.0% (19) of our random sample continuously fluctuated with amplitudes increasing with longer timescales, but the majority are close to the limits of detectability with Kepler. We discuss our techniques to mitigate the long term instrumental trends in Kepler light curves and our resulting structure function curves. The amplitudes of variability over four month periods, as seen in the structure functions and PSDs, can dramatically change for many of these AGN candidates. Four of the candidates have features in their Structure Functions that may indicate quasi-periodic behavior, although other possibilities are discussed.

astro-ph.HE↗

arXiv2014

SDSS1133: An Unusually Persistent Transient in a Nearby Dwarf Galaxy

While performing a survey to detect recoiling supermassive black holes, we have identified an unusual source having a projected offset of 800 pc from a nearby dwarf galaxy. The object, SDSS J113323.97+550415.8, exhibits broad emission lines and strong variability. While originally classified as a supernova (SN) because of its nondetection in 2005, we detect it in recent and past observations over 63 yr and find over a magnitude of rebrightening in the last 2 years. Using high-resolution adaptive optics observations, we constrain the source emission region to be <12 pc and find a disturbed host-galaxy morphology indicative of recent merger activity. Observations taken over more than a decade show narrow [O III] lines, constant ultraviolet emission, broad Balmer lines, a constant putative black hole mass over a decade of observations despite changes in the continuum, and optical emission-line diagnostics consistent with an active galactic nucleus (AGN). However, the optical spectra exhibit blueshifted absorption, and eventually narrow Fe II and [Ca II] emission, each of which is rarely found in AGN spectra. While this peculiar source displays many of the observational properties expected of a potential black hole recoil candidate, some of the properties could also be explained by a luminous blue variable star (LBV) erupting for decades since 1950, followed by a Type IIn SN in 2001. Interpreted as an LBV followed by a SN analogous to SN 2009ip, the multi-decade LBV eruptions would be the longest ever observed, and the broad Halpha emission would be the most luminous ever observed at late times (>10 yr), larger than that of unusually luminous supernovae such as SN 1988Z, suggesting one of the most extreme episodes of pre-SN mass loss ever discovered.

astro-ph.GA↗

arXiv2014

Discovery of a ~5 day characteristic timescale in the Kepler power spectrum of Zw 229-15

We present time series analyses of the full Kepler dataset of Zw 229-15. This Kepler light curve --- with a baseline greater than three years, composed of virtually continuous, evenly sampled 30-minute measurements --- is unprecedented in its quality and precision. We utilize two methods of power spectral analysis to investigate the optical variability and search for evidence of a bend frequency associated with a characteristic optical variability timescale. Each method yields similar results. The first interpolates across data gaps to use the standard Fourier periodogram. The second, using the CARMA-based time-domain modeling technique of Kelly et al. (2014), does not need evenly-sampled data. Both methods find excess power at high frequencies that may be due to Kepler instrumental effects. More importantly both also show strong bends (Δα ~ 2) at timescales of ~5 days, a feature similar to those seen in the X-ray PSDs of AGN but never before in the optical. This observed ~5 day timescale may be associated with one of several physical processes potentially responsible for the variability. A plausible association could be made with light-crossing, dynamical or thermal timescales, depending on the assumed value of the accretion disk size and on unobserved disk parameters such as α and H/R. This timescale is not consistent with the viscous timescale, which would be years in a ~10^7 Solar mass AGN such as Zw 229-15. However there must be a second bend on long (>~1 year) timescales, and that feature could be associated with the viscous timescale.

astro-ph.HE↗

arXiv2014

The fast UV variability of the active galactic nucleus in Fairall 9

We present results from a new optical/UV/X-ray monitoring campaign of the luminous Seyfert galaxy Fairall 9 using the Swift satellite. Using the UV-Optical Telescope (UVOT) on Swift, we find correlated optical/UV variability on all time scales ranging from the sampling time (4-days) to the length of the campaign (2.5 months). In one noteworthy event, the UW2-band flux dips by 20% in 4-days, and then recovers equally quickly; this event is not seen in either the optical or the X-ray bands. We argue that this event provides further evidence that a significant fraction of the UV-emission must be driven by irradiation/reprocessing of emission from the central disk. We also use an archival XMM-Newton observation to examine shorter time scale UV/X-ray variability. We find very rapid (<10 ks) UV flares of small amplitude. We show that, unless this emission is non-thermal, we must be seeing the Wien tail from a compact (<3 light hours), hot (T > $8\times10^4$ K) region. The possible association with X-ray microflares suggests that we may be seeing the UV signatures of direct X-ray flare heating of the innermost disk.

astro-ph.GA↗

arXiv2013

X-ray Transients in the Advanced LIGO/Virgo Horizon

Advanced LIGO and Advanced Virgo will be all-sky monitors for merging compact objects within a few hundred Mpc. Finding the electromagnetic counterparts to these events will require an understanding of the transient sky at low red-shift (z<0.1). We performed a systematic search for extragalactic, low red-shift, transient events in the XMM-Newton Slew Survey. In a flux limited sample, we found that highly-variable objects comprised 10% of the sample, and that of these, 10% were spatially coincident with cataloged optical galaxies. This led to 4x10^-4 transients per square degree above a flux threshold of 3x10^-12 erg cm-2 s-1 [0.2-2 keV] which might be confused with LIGO/Virgo counterparts. This represents the first extragalactic measurement of the soft X-ray transient rate within the Advanced LIGO/Virgo horizon. Our search revealed six objects that were spatially coincident with previously cataloged galaxies, lacked evidence for optical AGNs, displayed high luminosities around 10^43 erg s-1, and varied in flux by more than a factor of ten when compared with the ROSAT All-Sky Survey. At least four of these displayed properties consistent with previously observed tidal disruption events.

astro-ph.HE↗

arXiv2013

Suzaku View of the Swift/BAT Active Galactic Nuclei. V. Torus Structure of Two Luminous Radio-loud AGNs (3C 206 and PKS 0707-35)

We present the results from broad-band X-ray spectral analysis of 3C 206 and PKS 0707-35 with Suzaku and Swift/BAT, two of the most luminous unobscured and obscured radio-loud active galactic nuclei with hard X-ray luminosities of 10^{45.5} erg s^{-1} and 10^{44.9} erg s^{-1} (14--195 keV), respectively. Based on the radio core luminosity, we estimate that the X-ray spectrum of 3C 206 contains a significant (~ 60% in the 14--195 keV band) contribution from the jet, while it is negligible in PKS 0707-35. We can successfully model the spectra with the jet component (for 3C 206), the transmitted emission, and two reflection components from the torus and the accretion disk. The reflection strengths from the torus are found to be R_{torus} (= Ω/2π) = 0.29 +- 0.18 and 0.41 +- 0.18 for 3C 206 and PKS 0707-35, respectively, which are smaller than those in typical Seyfert galaxies. Utilizing the torus model by Ikeda et al. (2009), we quantify the relation between the half opening angle of a torus (θ_{oa}) and the equivalent width of an iron-K line. The observed equivalent width of 3C 206, < 71 eV, constrain the column density in the equatorial plane to N_{H}^{eq} < 10^{23} cm^{-2}, or the half opening angle to θ_{oa} > 80^\circ if N_{H}^{eq} = 10^{24} cm^{-2} is assumed. That of PKS 0707-35, 72 +- 36 eV, is consistent with N_{H}^{eq} ~ 10^{23} cm^{-2}. Our results suggest that the tori in luminous radio-loud AGNs are only poorly developed. The trend is similar to that seen in radio-quiet AGNs, implying that the torus structure is not different between AGNs with jets and without jets.

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arXiv2013

Searching for Cooling Signatures in Strong Lensing Galaxy Clusters: Evidence Against Baryons Shaping the Matter Distribution in Cluster Cores

The process by which the mass density profile of certain galaxy clusters becomes centrally concentrated enough to produce high strong lensing (SL) cross-sections is not well understood. It has been suggested that the baryonic condensation of the intra-cluster medium (ICM) due to cooling may drag dark matter to the cores and thus steepen the profile. In this work, we search for evidence of ongoing ICM cooling in the first large, well-defined sample of strong lensing selected galaxy clusters in the range 0.1 < z < 0.6. Based on known correlations between the ICM cooling rate and both optical emission line luminosity and star formation, we measure, for a sample of 89 strong lensing clusters, the fraction of clusters that have [OII]3727 emission in their brightest cluster galaxy (BCG). We find that the fraction of line-emitting BCGs is constant as a function of redshift for z > 0.2 and shows no statistically significant deviation from the total cluster population. Specific star formation rates, as traced by the strength of the 4000 angstrom break, D_4000, are also consistent with the general cluster population. Finally, we use optical imaging of the SL clusters to measure the angular separation, R_arc, between the arc and the center of mass of each lensing cluster in our sample and test for evidence of changing [OII] emission and D_4000 as a function of R_arc, a proxy observable for SL cross-sections. D_4000 is constant with all values of R_arc, and the [OII] emission fractions show no dependence on R_arc for R_arc > 10" and only very marginal evidence of increased weak [OII] emission for systems with R_arc < 10". These results argue against the ability of baryonic cooling associated with cool core activity in the cores of galaxy clusters to strongly modify the underlying dark matter potential, leading to an increase in strong lensing cross-sections.

astro-ph.CO↗

arXiv2013

Studying Faint Ultra Hard X-ray Emission from AGN in GOALS LIRGs with Swift BAT

We present the first analysis of the all-sky Swift BAT ultra hard X-ray (14-195 keV) data for a targeted list of objects. We find the BAT data can be studied at 3x fainter limits than in previous blind detection catalogs based on prior knowledge of source positions and using smaller energy ranges for source detection. We determine the AGN fraction in 134 nearby (z<0.05) luminous infrared galaxies (LIRGS) from the GOALS sample. We find that LIRGs have a higher detection frequency than galaxies matched in stellar mass and redshift at 14-195 keV and 24-35 keV. In agreement with work at other wavelengths, the AGN detection fraction increases strongly at high IR luminosity with half of high luminosity LIRGs (50%, 6/12, log L_IR/L_sun>11.8) detected. The BAT AGN classification shows 97% (37/38) agreement with Chandra and XMM AGN classification using hardness ratios or detection of a iron K-alpha line. This confirms our statistical analysis and supports the use of the Swift BAT all-sky survey to study fainter populations of any category of sources in the ultra hard X-ray band. BAT AGN in LIRGs tend to show higher column densities with 40\pm9% showing 14-195 keV/2-10 keV hardness flux ratios suggestive of high or Compton-thick column densities (log N_H>24 cm^-2), compared to only 12\pm5% of non-LIRG BAT AGN. We also find that using specific energy ranges of the BAT detector can yield additional sources over total band detections with 24% (5/21) of detections in LIRGs at 24-35 keV not detected at 14-195 keV.

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arXiv2012

The Black Hole Evolution and Space Time (BEST) Observatory

In this white paper, we discuss the concept of a next-generation X-ray mission called BEST (Black hole Evolution and Space Time). The mission concept uses a 3000 square centimeter effective area mirror (at 6 keV) to achieve unprecedented sensitivities for hard X-ray imaging spectrometry (5-70 keV) and for broadband X-ray polarimetry (2-70 keV). BEST can make substantial contributions to our understanding of the inner workings of accreting black holes, our knowledge about the fabric of extremely curved spacetime, and the evolution of supermassive black holes. BEST will allow for time resolved studies of accretion disks. With a more than seven times larger mirror area and a seven times wider bandpass than GEMS, BEST will take X-ray polarimetry to a new level: it will probe the time variability of the X-ray polarization from stellar mass and supermassive black holes, and it will measure the polarization properties in 30 independent energy bins. These capabilities will allow BEST to conduct tests of accretion disk models and the underlying spacetimes. With three times larger mirror area and ten times better angular resolution than NuSTAR, BEST will be able to make deep field observations with a more than 15 times better sensitivity than NuSTAR. The mission will be able to trace the evolution of obscured and unobscured black holes in the redshift range from zero to six, covering the most important epoch of supermassive black hole growth. The hard X-ray sensitivity of BEST will enable a deep census of non-thermal particle populations. BEST will give us insights into AGN feedback by measuring the particle luminosity injected by AGNs into the interstellar medium (ISM) of their hosts, and will map the emission from particles accelerated at large scale structure shocks. Finally, BEST has the potential to constrain the equation of state of neutron stars (NS).

astro-ph.IM↗