Long-wavelength Data Research Articles

Probabilistic and progressive deblended far-infrared and sub-millimetre point source catalogues

Context.Single-dish far-infrared (far-IR) and sub-millimetre (sub-mm) point source catalogues and their connections with galaxy catalogues at other wavelengths are of paramount importance to studying galaxy evolution. However, due to the large mismatch in spatial resolution, cross-matching galaxies detected at different wavelengths is not straightforward.Aims.This work aims to develop the next-generation deblended far-IR and sub-mm catalogues in deep extragalactic survey fields, by extracting photometry at the positions of known sources. We present the first application of our methodology in the COSMOS field.Methods.Our progressive deblending used the Monte Carlo Markov chain (MCMC)-based Bayesian probabilistic framework known as XID+. The deblending process started from theSpitzer/MIPS 24 μm data, using an initial prior list composed of sources selected from the COSMOS2020 catalogue and radio catalogues from the VLA and the MeerKAT surveys, based on spectral energy distribution (SED) modelling which predicts fluxes of the known sources at the deblending wavelength. To speed up flux prediction, we made use of a neural network-based emulator. After deblending the 24 μm data, we proceeded to theHerschelPACS (100 and 160 μm) and SPIRE wavebands (250, 350 and 500 μm). Each time we constructed a tailor-made prior list based on the predicted fluxes of the known sources, taking into account the deblended photometry from the previous steps.Results.Using simulated far-IR and sub-mm sky, we detailed the performance of our deblending pipeline. After validation with simulations, we then deblended the real observations from 24 to 500 μm and compared with blindly extracted catalogues and previous versions of deblended catalogues. As an additional test, we deblended the SCUBA-2 850 μm map and compared our deblended fluxes with ALMA measurements, demonstrating a higher level of flux accuracy compared to previous results. We publicly release our XID+ deblended point source catalogues, including best estimates and posterior probability distribution functions. These deblended long-wavelength data, which are cross-matched with multi-band photometry by construction, are crucial for studies such as deriving the fraction of dust-obscured star formation and better separation of quiescent galaxies from dusty star-forming galaxies.

JWST Observations of the Enigmatic Y-Dwarf WISE 1828+2650. I. Limits to a Binary Companion

The Y-dwarf WISE 1828+2650 is one of the coldest known brown dwarfs with an effective temperature of ∼300 K. Located at a distance of just 10 pc, previous model-based estimates suggest WISE1828+2650 has a mass of ∼5–10 M J, making it a valuable laboratory for understanding the formation, evolution, and physical characteristics of gas giant planets. However, previous photometry and spectroscopy have presented a puzzle, with the near impossibility of simultaneously fitting both the short- (0.9–2.0 μm) and long-wavelength (3–5 μm) data. A potential solution to this problem has been the suggestion that WISE 1828+2650 is a binary system whose composite spectrum might provide a better match to the data. Alternatively, new models being developed to fit JWST/NIRSpec, and MIRI spectroscopy might provide new insights. This article describes JWST/NIRCam observations of WISE 1828+2650 in six filters to address the binarity question and to provide new photometry to be used in model fitting. We also report adaptive optics imaging with the Keck I0 m telescope. We find no evidence for multiplicity for a companion beyond 0.5 au with either JWST or Keck. Companion articles will present low- and high-resolution spectra of WISE 1828 obtained with both NIRSpec and MIRI.

Properties of dust in the North - East part of Perseus Cloud within the open cluster IC 348 using data from IRIS and AKARI

In this work, we have studied the dust properties of the North-East part of Perseus cloud having a size of 0.5o × 0.5o located at RA (ICRS): 56.14o DEC (ICRS): +32.15o, within the Open Cluster IC 348, using IRIS and AKARI data. An isolated region of size 0.39o×0.23o in IRIS and 0.34o×0.16o in AKARI data is detected within it. The infrared fluxes extracted using Aladin v11.0 are used to study the dust temperature and dust mass. The distance of the selected dust structure is calculated using Gaia EDR3, which is 309.98 pc. The infrared flux density is found to be increased for long-wavelength data. The average dust color temperature calculated from short-wavelength IRIS data is more than that calculated from long-wavelength AKARI data, which are 26.34 K±0.11 K for IRIS and 17.63 K±0.02 K for AKARI data. The mass of dust within the entire dust structure is 0.06 Mʘ for IRIS data and 37.44 Mʘ for AKARI data. Jeans mass for isolated region gives contradictory results in two surveys, for IRIS survey total mass is smaller than Jeans mass but for AKARI survey the total mass is larger than the Jeans mass. A good correlation between infrared fluxes is noticed for linear regression. The study background sources observed from the SIMBAD database explore the large number of stars, X-ray sources, YSOs, etc., embedded within the dust structure; some of them are responsible for dust heating and some for the contribution of dust mass. The contour map shows the identical distribution between infrared fluxes, dust color temperature and Planck’s function and dissimilar distribution between dust mass and visual extinction in IRIS and AKARI data. The high temperature at the central region suggests that the core of dust structure is thermally active, radiating the large thermal radiation in comparison to the outer region.

Spectral consistency of satellite and airborne data: Application of an equivalent dipole layer for combining satellite and aeromagnetic data sets

We present a novel approach for the combination of aeromagnetic and satellite data applying an equivalent dipole layer and spherical harmonic (SH) expansion of the dipoles. The method involves two steps: (1) inversion for the magnetic parameters of the equivalent dipole layer and (2) conversion of the magnetic parameters into SH coefficients. With this approach, SH analysis can be used for a regional study area, and, for example, the long-wavelength range of aeromagnetic data can be replaced with satellite data. We test our approach on the third, fourth, and fifth editions of the Magnetic Anomaly Map of Australia, which were releveled using independent aeromagnetic data sets for long-wavelength correction. The results indicate that the magnetic compilations leveled to long-haul control lines have a good agreement with the LCS-1 satellite model in the range of SH degree 40 to 110 (corresponding to half-wavelengths between 180 to 500 km), whereas the third edition of the Magnetic Anomaly Map of Australia demonstrates poor control over long- wavelengths in this spectral range. Our analysis suggests that even the carefully processed fifth edition would benefit from the replacement of long-wavelength data with satellite data.

Real astronomy data for anyone: Explore NASA’s IRSA

Many professional astronomy archives are open to the public; software tools are getting better all the time to not just access these data, but also work with them. The Infrared [IR] Science Archive (IRSA) is NASA’s home for long-wavelength data, both space- and ground-based. You can use this interface to pull data to create your own lessons, or turn students loose in the archive to discover features of our multi-wavelength universe.

Interpretation of satellite gravity anomalies with pseudo-depth slicing method filter in Turkey

In this study, discontinuities and major tectonic boundaries are interpreted in and around Turkey by Bouguer gravity anomaly. The World Gravity Map 2012 Bouguer anomaly is used for the interpretation of major tectonic features in the Anatolia Region. The World Gravity Map 2012 comprises land, marine, airborne surveys as well as altimetry and gravity satellite measurements. Radial average power spectrum (RAPS) and band-pass filtering are used for long and short wavelength separation. Short wavelength anomalies are generally associated with the shallower geological structures whereas long-wavelength data result from the deeper source. For the whole study area, four depth segments are detected. Moreover, the radial average depths of these depth segments are 54.9 km, 32.2 km, 21.9 km and 8.0 km. In order to conduct better interpretation, the study area was divided into three subareas from the west to the east (area 1 to area 3). In area 1 (41.4 km, 21.2 km and 7.8 km) and area 2 (48.1 km, 20.0 km and 6.6 km), three depth sources are detected. Furthermore, four various depth segments are analysed in area 3 (54.3 km, 29.8 km, 20.8 km and 8.6 km). The present study was designed to interpret the whole study area and the sub-areas (area 1, area 2 and area 3) via combined geophysical and qualitative interpretation techniques. In order to justify the qualitative interpretation, a quantitative edge detection method is used. The interpretation of the whole study area, area 1, area 2 and area 3 showed that depth of the sediment accumulation in the Western Anatolia is estimated as 7.8 km. Furthermore, crustal thickening in the Eastern Anatolia is interpreted from pseudo-depth slices.

Crystal Structure of the Vanadate-Inhibited Ca2+-ATPase

Vanadate is the hallmark inhibitor of the P-type ATPase family; however, structural details of its inhibitory mechanism have remained unresolved. We have determined the crystal structure of sarcoplasmic reticulum Ca(2+)-ATPase with bound vanadate in the absence of Ca(2+). Vanadate is bound at the catalytic site as a planar VO3(-) in complex with water and Mg(2+) in a dephosphorylation transition-state-like conformation. Validating bound VO3(-) by anomalous difference Fourier maps using long-wavelength data we also identify a hitherto undescribed Cl(-) site near the dephosphorylation site. Crystallization was facilitated by trinitrophenyl (TNP)-derivatized nucleotides that bind with the TNP moiety occupying the binding pocket that normally accommodates the adenine of ATP, rationalizing their remarkably high affinity for E2P-like conformations of the Ca(2+)-ATPase. A comparison of the configurations of bound nucleotide analogs in the E2·VO3(-) structure with that in E2·BeF3(-) (E2P ground state analog) reveals multiple binding modes to the Ca(2+)-ATPase.

Dust emissivity in the star-forming filament OMC 2/3

We present new measurements of the dust emissivity index, beta, for the high-mass, star-forming OMC 2/3 filament. We combine 160-500 um data from Herschel with long-wavelength observations at 2 mm and fit the spectral energy distributions across a ~ 2 pc long, continuous section of OMC 2/3 at 15000 AU (0.08 pc) resolution. With these data, we measure beta and reconstruct simultaneously the filtered-out large-scale emission at 2 mm. We implement both variable and fixed values of beta, finding that beta = 1.7 - 1.8 provides the best fit across most of OMC 2/3. These beta values are consistent with a similar analysis carried out with filtered Herschel data. Thus, we show that beta values derived from spatial filtered emission maps agree well with those values from unfiltered data at the same resolution. Our results contradict the very low beta values (~ 0.9) previously measured in OMC 2/3 between 1.2 mm and 3.3 mm data, which we attribute to elevated fluxes in the 3.3 mm observations. Therefore, we find no evidence or rapid, extensive dust grain growth in OMC 2/3. Future studies with Herschel data and complementary ground-based long-wavelength data can apply our technique to obtain robust determinations of beta in nearby cold molecular clouds.

The spectral energy distribution of the redshift 7.1 quasar ULAS J1120+0641

We present new observations of the highest-redshift quasar known, ULAS J1120+0641, redshift $z=7.084$, obtained in the optical, at near-, mid-, and far-infrared wavelengths, and in the sub-mm. We combine these results with published X-ray and radio observations to create the multiwavelength spectral energy distribution (SED), with the goals of measuring the bolometric luminosity $L_{\rm bol}$, and quantifying the respective contributions from the AGN and star formation. We find three components are needed to fit the data over the wavelength range $0.12-1000\,\mu$m: the unobscured quasar accretion disk and broad-line region, a dusty clumpy AGN torus, and a cool 47K modified black body to characterise star formation. Despite the low signal-to-noise ratio of the new long-wavelength data, the normalisation of any dusty torus model is constrained within $\pm40\%$. We measure a bolometric luminosity $L_{\rm bol}=2.6\pm0.6\times10^{47}\,$erg$\,$s$^{-1}=6.7 \pm 1.6\times10^{13}L_{\odot}$, to which the three components contribute $31\%,32\%,3\%$, respectively, with the remainder provided by the extreme UV $<0.12\,\mu$m. We tabulate the best-fit model SED. We use local scaling relations to estimate a star formation rate (SFR) in the range $60-270\,{\rm M}_\odot$/yr from the [C$\,{\scriptsize \rm II}$] line luminosity and the $158\,\mu$m continuum luminosity. An analysis of the equivalent widths of the [C$\,{\scriptsize \rm II}$] line in a sample of $z>5.7$ quasars suggests that these indicators are promising tools for estimating the SFR in high-redshift quasars in general. At the time observed the black hole was growing in mass more than 100 times faster than the stellar bulge, relative to the mass ratio measured in the local universe, i.e. compared to ${M_{\rm BH}}/{M_{\rm bulge}} \simeq 1.4\times10^{-3}$, for ULAS J1120+0641 we measure ${\dot{M}_{\rm BH}}/{\dot{M}_{\rm bulge}} \simeq 0.2$.

MULTI-WAVELENGTH RADIO CONTINUUM EMISSION STUDIES OF DUST-FREE RED GIANTS

Multi-wavelength centimeter continuum observations of non-dusty, non-pulsating K spectral-type red giants directly sample their chromospheres and wind acceleration zones. Such stars are feeble emitters at these wavelengths however, and previous observations have provided only a small number of modest S/N measurements slowly accumulated over three decades. We present multi-wavelength Karl G. Jansky Very Large Array thermal continuum observations of the wind acceleration zones of two dust-free red giants, Arcturus (Alpha Boo: K2 III) and Aldebaran (Alpha Tau: K5 III). Importantly, most of our observations of each star were carried out over just a few days, so that we obtained a snapshot of the different stellar atmospheric layers sampled at different wavelengths, independent of any long-term variability. We report the first detections at several wavelengths for each star including a detection at 10 cm (3.0 GHz: S band) for both stars and a 20 cm (1.5 GHz: L band) detection for Alpha Boo. This is the first time single luminosity class III red giants have been detected at these continuum wavelengths. Our long-wavelength data sample the outer layers of Alpha Boo's atmosphere where its wind velocity is approaching its terminal value and the ionization balance is becoming frozen-in. For Alpha Tau, however, our long-wavelength data are still sampling its inner atmosphere, where the wind is still accelerating probably due to its lower mass-loss rate. We compare our data with published semi-empirical models based on ultraviolet data, and the marked deviations highlight the need for new atmospheric models to be developed. Spectral indices are used to discuss the possible properties of the stellar atmospheres, and we find evidence for a rapidly cooling wind in the case of Alpha Boo. Finally, we develop a simple analytical wind model for Alpha Boo based on our new long-wavelength flux measurements.

The Chang’E-1 orbiter plays a distinctive role in China’s first successful selenodetic lunar mission

The first Chinese lunar orbiter Chang’E-1 is a successful mission with many fruitful results obtained in various disciplines. The scientific data acquired by the Chang’E-1 payloads can benefit studies of the lunar origin and evolution, as well as other relevant research areas, after careful validation of the data. Among the new results, the Chang’E-1 selenodetic products are continually uncovering characteristics of the lunar surface, undersurface and inner structure. Successful lunar orbiters such as the Clementine, Lunar Prospector, KAGUYA/SELENE, Chang’E-1, Lunar Reconnaissance Orbiter and GRAIL have been revealing, with increasing clarity, global selenodetic characteristics with state-of-the-art fine resolution and high precision. In particular, the Chang’E-1 plays an important distinctive role in selenodetic exploration through enhancing lunar topography and gravity models. The gravity model has been successfully improved with a factor of two after applying the Chang’E-1 long-wavelength tracking data. Using the new models, some medium-scale lunar surface characteristics such as basins and volcanoes have been identified. Furthermore, the old mascon basins of Bouguer, gravity anomaly and craters have been discovered with the Chang’E-1 selenodetic data.

Predicting dust extinction from the stellar mass of a galaxy

We investigate how the typical dust extinction of H-alpha luminosity from a star-forming galaxy depends upon star formation rate (SFR), metallicity and stellar mass independently, using a sample of ~90,000 galaxies from Data Release 7 of the Sloan Digital Sky Survey (SDSS). We measure extinctions directly from the Balmer decrement of each source, and while higher values of extinction are associated with an increase in any of the three parameters, we demonstrate that the fundamental property that governs extinction is stellar mass. After this mass-dependent relationship is removed, there is very little systematic dependence of the residual extinctions with either SFR or metallicity, and no significant improvement is obtained from a more general parameterisation. In contrast to this, if either a SFR-dependent or metallicity-dependent extinction relationship is applied, the residual extinctions show significant trends that correlate with the other parameters. Using the SDSS data, we present a relationship to predict the median dust extinction of a sample of galaxies from its stellar mass, which has a scatter of ~0.3 mag. The relationship was calibrated for H-alpha emission, but can be more generally applied to radiation emitted at other wavelengths. These results have important applications for studies of high-redshift galaxies, where individual extinction measurements are hard to obtain but stellar mass estimates can be relatively easily estimated from long-wavelength data.

Pyrometric Method of Temperature Measurement with Compensation for Solar Radiation

Pyrometric Method of Temperature Measurement with Compensation for Solar RadiationOutdoor remote temperature measurements in the infrared range can be very inaccurate because of the influence of solar radiation reflected from a measured object. In case of strong directional reflection towards a measuring device, the error rate can easily reach hundreds per cent as the reflected signal adds to the thermal emission of an object. As a result, the measured temperature is much higher than the real one. Error rate depends mainly on the emissivity of an object and intensity of solar radiation. The position of the measuring device with reference to an object and the Sun is also important. The method of compensation of such undesirable influence of solar radiation will be presented. It is based on simultaneous measurements in two different spectral bands, shor-twavelength and long-wavelength ones. The temperature of an object is derived from long-wavelength data only, whereas the short-wavelength band, the corrective one, is used to estimate the solar radiation level. Both bands were selected to achieve proportional changes of the output signal due to solar radiation. Knowing the relation between emissivity and solar radiation levels in both spectral bands, it is possible to reduce the measurement error several times.

58 RADIO SOURCES NEAR BRIGHT NATURAL GUIDE STARS,

We present a preliminary survey of 58 radio sources within the isoplanatic patches (r < 25'') of bright (11 < R < 12) stars suitable for use as natural guide stars with high-order adaptive optics (AO). An optical and near-infrared imaging survey was conducted utilizing tip-tilt corrections in the optical and AO in the near-infrared. Spectral energy distributions were fit to the multi-band data for the purpose of obtaining photometric redshifts using the Hyperz code. Several of these photometric redshifts were confirmed with spectroscopy, a result that gives more confidence to the redshift distribution for the whole sample. Additional long-wavelength data from Spitzer, SCUBA, SHARC2, and VLA supplement the optical and near-infrared data. We find the sample generally follows and extends the magnitude–redshift relation found for more powerful local radio galaxies. The survey has identified several reasonably bright (H = 19 − 20) objects at significant redshifts (z > 1) that are now within the capabilities of the current generation of AO-fed integral-field spectrographs. These objects constitute a unique sample that can be used for detailed ground-based AO studies of galactic structure, evolution, and active galactic nucleus formation at high redshift.

THE ATOMIC STRUCTURE AND HYDROGEN BONDING OF DEUTERATED MELANTERITE, FeSO4{middle dot}7D2O

The atomic structure of synthetic, deuterated melanterite (FeSO4·7D2O), a 14.0774(9), b 6.5039(4), c 11.0506(7) A, β 105.604(1)°, space group P 21/ c , Z = 4, has been refined from the combined refinement of 2.3731(1) A and 1.3308 A neutron powder-diffraction data to a R wp (tot) = 3.01% and R p (tot) = 2.18%. Both the short- and long-wavelength data were required to obtain a satisfactory fit in the Rietveld refinement. The results of this study confirm the previously proposed H-bonding scheme for melanterite. Small but significant variations of the Fe–O bond lengths are attributed to details of the hydrogen bonds to the oxygen atoms of the Fe octahedra. We draw comparisons between the monoclinic and orthorhombic heptahydrate sulfate minerals associated with mine wastes and relate differences in the structure to strengths and weaknesses in their H-bond networks.

On the routine use of soft X-rays in macromolecular crystallography. Part IV. Efficient determination of anomalous substructures in biomacromolecules using longer X-ray wavelengths

23 different crystal forms of 19 different biological macromolecules were examined with respect to their anomalously scattering substructures using diffraction data collected at a wavelength of 2.0 A (6.2 keV). In more than 90% of the cases the substructure was found to contain more than just the protein S atoms. The data presented suggest that chloride, sulfate, phosphate or metal ions from the buffer or even from the purification protocol are frequently bound to the protein molecule and that these ions are often overlooked, especially if they are not bound at full occupancy. Thus, in order to fully describe the macromolecule under study, it seems desirable that any structure determination be complemented with a long-wavelength data set.

Penetrating the Deep Cover of Compton‐thick Active Galactic Nuclei

We analyze observations obtained with the Chandra X-ray Observatory of bright Compton thick active galactic nuclei (AGNs), those with column densities in excess of 1.5 x 10^{24} cm^{-2} along the lines of sight. We therefore view the powerful central engines only indirectly, even at X-ray energies. Using high spatial resolution and considering only galaxies that do not contain circumnuclear starbursts, we reveal the variety of emission AGNs alone may produce. Approximately 1% of the continuum's intrinsic flux is detected in reflection in each case. The only hard X-ray feature is the prominent Fe K alpha fluorescence line, with equivalent width greater than 1 keV in all sources. The Fe line luminosity provides the best X-ray indicator of the unseen intrinsic AGN luminosity. In detail, the morphologies of the extended soft X-ray emission and optical line emission are similar, and line emission dominates the soft X-ray spectra. Thus, we attribute the soft X-ray emission to material that the central engines photoionize. Because the resulting spectra are complex and do not reveal the AGNs directly, crude analysis techniques such as hardness ratios would mis-classify these galaxies as hosts of intrinsically weak, unabsorbed AGNs and would fail to identify the luminous, absorbed nuclei that are present. We demonstrate that a three-band X-ray diagnostic can correctly classify Compton thick AGNs, even when significant soft X-ray line emission is present. The active nuclei produce most of the galaxies' total observed emission over a broad spectral range, and much of their light emerges at far-infrared wavelengths. Stellar contamination of the infrared emission can be severe, however, making long-wavelength data alone unreliable indicators of the buried AGN luminosity.

Probing the birth of super star clusters: Implications for massive star formation

Super star clusters are one of the most extreme star forming environments in the universe, and the most massive and dense of these may be proto globular clusters. Like individual massive stars, the earliest stages of super star cluster evolution are deeply obscured, and therefore our knowledge about their birth environments is currently very incomplete. However, the study of natal super star clusters has become somewhat of a cottage industry in recent years, and the sample of such objects has been growing rapidly with high-quality long-wavelength data now available from a number of observatories. The natal super star clusters identified in thermal-infrared and radio observations represent the youngest stage of massive star cluster evolution yet observed. Their properties appear to be similar to those of ultracompact h II regions in the milky way, but scaled up in total mass and luminosity. I will overview what we think we know about these objects based on existing observations, discuss their relationship to ultracompact h II regions, present new models of their spectral energy distributions based on 3-d simulations, and outline some of the most significant gaps in our current understanding.

The Cosmic Evolution of Hard X-Ray-selected Active Galactic Nuclei

We use highly spectroscopically complete deep and wide-area Chandra surveys to determine the cosmic evolution of hard X-ray–selected active galactic nuclei (AGNs). For the deep fields, we supplement the spectroscopic redshifts with photometric redshifts to assess where the unidentified sources are likely to lie. We find that the median redshifts are fairly constant with X-ray flux at z ~ 1. We classify the optical spectra and measure the FWHM line widths. Most of the broad-line AGNs show essentially no visible absorption in X-rays, whereas the sources without broad lines (FWHM < 2000 km s-1; AGNs) show a wide range of absorbing column densities. We determine hard X-ray luminosity functions for all spectral types with LX ≥ 1042 ergs s-1 and for broad-line AGNs alone. At z < 1.2, both are well described by pure luminosity evolution, with L* evolving as (1 + z)3.2±0.8 for all spectral types and as (1 + z)3.0±1.0 for broad-line AGNs alone. Thus, all AGNs drop in luminosity by almost an order of magnitude over this redshift range. We show that this observed drop is due to AGN downsizing rather than to an evolution in the accretion rates onto the supermassive black holes. We directly compare our broad-line AGN hard X-ray luminosity functions with the optical QSO luminosity functions and find that at the bright end they agree extremely well at all redshifts. However, the optical QSO luminosity functions do not probe faint enough to see the downturn in the broad-line AGN hard X-ray luminosity functions and even appear to be missing some sources at the lowest luminosities they probe. We find that broad-line AGNs dominate the number densities at the higher X-ray luminosities, while optically narrow AGNs dominate at the lower X-ray luminosities. We rule out galaxy dilution as a partial explanation for this effect by measuring the nuclear UV/optical properties of the Chandra sources using the Hubble Space Telescope Advanced Camera for Surveys GOODS-North data. The UV/optical nuclei of the optically narrow AGNs are much weaker than expected if the optically narrow AGNs were similar to the broad-line AGNs. We therefore postulate the need for a luminosity-dependent unified model. An alternative possibility is that the broad-line AGNs and the optically narrow AGNs are intrinsically different source populations. We cover both interpretations by constructing composite spectral energy distributions—including long-wavelength data from the mid-infrared to the submillimeter—by spectral type and by X-ray luminosity. We use these spectral energy distributions to infer the bolometric corrections (from hard X-ray luminosities to bolometric luminosities) needed to map the accretion history. We determine the accreted supermassive black hole mass density for all spectral types and for broad-line AGNs alone, using the observed evolution of the hard X-ray energy density production rate and our inferred bolometric corrections. We find that only about one-half to one-quarter of the supermassive black hole mass density was fabricated in broad-line AGNs. Using either recent optical QSO luminosity function determinations or our broad-line AGN hard X-ray luminosity function determinations, we measure an accreted supermassive black hole mass density that is a factor of almost 2 lower than that measured by previous work, assuming = 0.1. This leaves room for obscured accretion when compared with the local supermassive black hole mass density. In fact, we find reasonable agreement between the accreted supermassive black hole mass density from all spectral types and the local supermassive black hole mass density, assuming ≈ 0.1–0.2. However, there is little room for further obscured sources or for low-efficiency accretion periods.

Regional–residual Gravity Field Separation in the Central Andes using Global Geopotential Models

Traditional methods of regional?residual gravity field separation typically involve high-pass filtering, low-order polynomial fitting or computations using isostatic models. All of these methods are susceptible to ambiguity and subjectivity in the selection of filter parameters, polynomial degree and isostatic model. Global Geopotential Models (GGMs), on the other hand, provide long-wavelength gravity data that are based on observations. Therefore, they have the potential to be used to more objectively define the regional gravity field and to give residual anomalies with reduced ambiguity. We have examined residual gravity anomalies in the Central Andes computed using a regional field defined by the recent EIGEN?GRACE01S satellite-only GGM. The resulting residual anomalies show significant correlations with the active volcanic arc and the geometry of the subducting Nazca plate. These results suggest that GGMs have a place in regional gravity interpretation, but the advantages over existing techniques remain to be thoroughly tested.