449 research outputs found
Fast Multipole Method for Gravitational Lensing: Application to High-magnification Quasar Microlensing
We introduce the use of the fast multipole method (FMM) to speed up gravitational lensing ray tracing calculations. The method allows very fast calculation of ray deflections when a large number of deflectors, N-*, are involved, while keeping rigorous control on the errors. In particular, we apply this method, in combination with the inverse polygon mapping (IPM) technique, to quasar microlensing to generate microlensing magnification maps with very high workloads (high magnification, large size, and/or high resolution) that require a very large number of deflectors. Using FMM-IPM, the computation time can be reduced by a factor of similar to 10(5) with respect to standard inverse ray shooting (IRS), making the use of this algorithm on a personal computer comparable to the use of standard IRS on GPUs. We also provide a flexible web interface for easy calculation of microlensing magnification maps using FMM-IPM (see https://gloton.ugr.es/microlensing/). We exemplify the power of this new method by applying it to some challenging interesting astrophysical scenarios, including clustered primordial black holes and extremely magnified stars close to the giant arcs of galaxy clusters. We also show the performance/use of FMM to calculate ray deflection for a halo resulting from cosmological simulations composed of a large number (N (sic) 10(7)) of elements.MCIN/AEI PID2020-118687GB-C33
PID2020-118687GB-C31Junta de Andalucia FQM-108, P20_00334
A-FQM-510-UGR20/FEDE
Revealing the structure of the lensed quasar Q 0957+561 III. Constraints on the size of the broad-line region
Aims. Our aim is to examine the size, kinematics, and geometry of the broad-line region (BLR) in the double-lensed quasar Q 0957+561 by analyzing the impact of microlensing on various rest-frame ultraviolet broad-emission lines (BELs).
Methods. We explore the influence of intrinsic variability and microlensing on the C IV, C III], and Mg II emission lines through multiple spectroscopic observations taken between April 1999 and January 2017. By utilizing the line cores as a reference for no microlensing and correcting for the long time delay between the images, we estimate the sizes of the regions emitting the broad-line wings using a Bayesian approach.
Results. Our study of the microlensing amplitudes between the lensed images of the quasar Q 0957+561 reveals differing sizes of the regions emitting the three prominent BELs C IV, C III], and Mg II. The strength of the differential microlensing indicates that the high-ionization line C IV arises from a compact inner region of the BLR with a half-light radius of R1/2 ≳ 16.0 lt-days, which represents a lower limit on the overall size of the BLR and is comparable to the size of the region emitting the r-band continuum in this system. A somewhat larger size of R1/2 ≳ 44 lt-days is obtained for the semi-forbidden line C III]. Microlensing has a weak impact on the lower-ionization line Mg II, which is emitted from a region with a half-light radius of R1/2 ≳ 50 lt-days. These findings suggest that the BEL regions may have distinct geometries and kinematics, with the more extended ones being spherically symmetric, and the most compact ones being nonspherical, with motions likely confined to a plan
Revealing the structure of the lensed quasar Q 0957+561 II. Supermassive black hole mass via gravitational redshift
Aims. We intend to use the impact of microlensing on the Fe III lambda lambda 2039 2113 emission line blend along with a measure of its gravitational redshift to estimate the mass of the quasar's central supermassive black hole (SMBH).
Methods. We fit the Fe III feature in multiple spectroscopic observations between 2008 and 2016 of the gravitationally lensed quasar Q 0957 +561 with relatively high signal-to-noise ratios (at the adequate wavelength). Based on the statistics of microlensing magnifications, we used a Bayesian method to derive the size of its emitting region.
Results. The Fe III lambda lambda 2039 2113 spectral feature appears systematically redshifted in all epochs of observation by a value of Delta lambda similar to 17 angstrom on average. We find clear di fferences in the shape of the Fe III line blend between images A and B. Measuring the strength of those magnitude di fferences, we conclude that this blend may arise from a region of half-light radius of R-1/2 similar to 15 ltdays, which is in good agreement with the accretion disk dimensions for this system. We obtain a mass for the central SMBH of M-BH = 1.5(-0.5)(+0.5) x 10(9) M-circle dot, consistent within uncertainties with previous mass estimates based on the virial theorem. The relatively small uncertainties in the mass determination (<35%) make this method a compelling alternative to other existing techniques (e.g., the virial plus reverberation mapping based size) for measuring black hole masses. Combining the Fe III lambda lambda 2039 2113 redshift based method with the virial, we estimate a virial factor in the f similar to 1:2 1:7 range for this system.Tel Aviv UniversityUniversity of Haifa through a DFG grant HA3555-14/1Spanish Government AYA2016- 79104-C3-1-P
AYA2016-79104-C3-3-PCenter for Forestry Research & Experimentation (CIEF)European Commission Prometeo/2020/085Spanish Government AYA2014-53506-PEuropean Commission
Spanish Government AYA2014-53506-PJunta de Andalucia FQM-108Centro de Astrofisica de Valparaiso (CAV
Limiting the Abundance of LIGO/Virgo Black Holes with Microlensing Observations of Quasars of Finite Size
We thank the anonymous referee for ideas and comments, which greatly contributed to enhancing the scope of our paper. This research was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) with the grants AYA2016-79104-C3-1-P and AYA2016-79104-C3-3-P. J.J.V. is supported by the project AYA2017-84897-P financed by MINECO and by the Fondo Europeo de Desarrollo Regional (FEDER), and by projects FQM-108, P20_00334, and A-FQM-510-UGR20/FEDER financed by Junta de Andalucia. A.E.G. thanks the support from grant FPI-SO from MINECO (research project SEV-2015-0548-17-4 and predoctoral contract BES-2017-082319).We present a simple but general argument that strongly limits the abundance of primordial black holes (PBHs) (or
other unknown population of compact objects) with masses similar to those determined by LIGO/Virgo from BH
binary mergers. We show that quasar microlensing can be very sensitive to the mass of the lenses, and that it is able
to distinguish between stars and BHs of high mass, when the finite size of the source is taken into account. A
significant presence of massive BHs would produce frequent high-flux magnifications (except for unrealistically
large sources), which have been very rarely observed. On the contrary, a typical stellar population would induce
flux magnifications consistent with the observations. This result excludes PBHs (or any type of compact object) in
the mass range determined by LIGO/Virgo as the main dark matter constituents in the lens galaxies.Spanish Government AYA2016-79104-C3-1-P
AYA2016-79104-C3-3-P
AYA2017-84897-PEuropean CommissionSpanish GovernmentJunta de Andalucia FQM-108
P20_00334
A-FQM-510-UGR20/FEDERgrant FPI-SO from MINECO SEV-2015-0548-17-4
BES-2017-08231
MEGADES: MEGARA galaxy disc evolution survey
The main interest of the science team for the exploitation of the MEGARA instrument at the 10.4m Gran Telescopio Canarias (GTC)
is devoted to the study of nearby galaxies. The focus lies on researching the history of star formation, and the chemical and kinematical
properties of disc systems. We refer to this project as MEGADES: the MEGARA galaxy disc evolution survey. The initial goal of
MEGADES is to provide a detailed study of the inner regions of nearby disc galaxies in terms of their spectrophotometric and chemical
evolution, and to provide a dynamical characterisation by distinguishing the contribution of in situ and ex situ processes to the history of
star formation and effective chemical enrichment of these regions. In addition, the dynamical analysis of these inner regions naturally
includes the identification and characterisation of galactic winds that might be present in these regions. At a later stage, we will extend
this study farther out in galactocentric distance. The first stage of this project encompasses the analysis of the central regions of 43
nearby galaxies observed with the MEGARA integral field unit for ∼114 h, including both guaranteed time and open time observations.
In this paper we provide a set of all the processed data products available to the community and early results from the analysis of these
data regarding stellar continuum and ionised and neutral gas features.GRANTECANEuropean Regional Development Funds (ERDF), through Programa Operativo Canarias FEDER 2014-2020Ministry of Science and Innovation, Spain (MICINN)
Spanish GovernmentNational Aeronautics & Space Administration (NASA)National Science Foundation (NSF)University of MarylandEotvos Lorand University (ELTE) RTI2018-096188-B-I00
AYA2016-75808-R
MCIN/AEI/10.13039/501100011033United States Department of Energy (DOE)
Los Alamos National Laboratory NNX08AR22GGordon and Betty Moore Foundation AST-123887
Abundance of LIGO/Virgo Black Holes from Microlensing Observations of Quasars with Reverberation Mapping Size Estimates
We thank the anonymous referees for ideas and comments that greatly contributed to enhancing the scope of our paper. This research was supported by the Spanish Ministry of Economy and Competitiveness (MINECO) with grants AYA2016-79104-C3-1-P and AYA2016-79104-C3-3-P and projects PID2020-118687GB-C33, PID2020-118687GB-C32, and PID2020-118687GB-C31, financed by MCIN/AEI/10.13039/501100011033. J.J.V. is supported by project AYA2017-84897-P, financed by the Spanish MINECO and by the Fondo Europeo de Desarrollo Regional (FEDER), and by projects FQM-108, P20_00334 and A-FQM-510-UGR20/FEDER, financed by Junta de Andalucia. A.E.G. is grateful for the support from grant FPI-SO from the Spanish MINECO (research project SEV-2015-0548-17-4 and predoctoral contract BES-2017-082319).Assuming a population of black holes (BHs) with masses in the range inferred by LIGO/Virgo from BH mergers, we use quasar microlensing observations to estimate their abundances. We consider a mixed population of stars and BHs and the presence of a smooth dark matter component. We adopt reverberation mapping estimates of the quasar size. According to a Bayesian analysis of the measured microlensing magnifications, a population of BHs with masses similar to 30M (circle dot) constitutes less than 0.4% of the total matter at the 68% confidence level (less than 0.9% at the 90% confidence level). We have explored the whole mass range of LIGO/Virgo BHs, finding that this upper limit ranges from 0.5% to 0.4% at the 68% confidence level (from 1.1% to 0.9% at the 90% confidence level) when the BH masses change from 10 to 60M (circle dot). We estimate a 16% contribution from the stars, in agreement with previous studies based on a single-mass population that do not explicitly consider the presence of BHs. These results are consistent with the estimates of BH abundances from the statistics of LIGO/Virgo mergers, and rule out primordial BHs (or any other types of compact object) in this mass range constituting a significant fraction of the dark matter.Spanish Ministry of Economy and Competitiveness (MINECO) - MCIN/AEI AYA2016-79104-C3-1-P
AYA2016-79104-C3-3-P
PID2020-118687GB-C33
PID2020-118687GB-C32
PID2020-118687GB-C31Spanish Government AYA2017-84897-P
SEV-2015-0548-17-4
BES-2017-082319European CommissionSpanish Government AYA2017-84897-PJunta de Andalucia FQM-108
P20_00334
A-FQM-510-UGR20/FEDE
Quasar Microlensing Statistics and Flux-ratio Anomalies in Lens Models
Precise lens modeling is a critical step in time delay studies of multiply imaged quasars, which are key for measuring some important cosmological parameters (especially H0). However, lens models (in particular those semi-automatically generated) often show discrepancies with the observed flux ratios between the different quasar images. These flux-ratio anomalies are usually explained through differential effects between images (mainly microlensing) that alter the intrinsic magnification ratios predicted by the models. To check this hypothesis, we collect direct measurements of microlensing to obtain the histogram of microlensing magnifications. We compare this histogram with recently published model flux-ratio anomalies and conclude that they cannot be statistically explained by microlensing. The average value of the model anomalies (0.74 mag) significantly exceeds the mean impact of microlensing (0.33 mag). Moreover, the histogram of model anomalies presents a significant tail with high anomalies (∣Δm∣ ≥ 0.7 mag), which is completely unexpected from the statistics of microlensing observations. Microlensing simulations neither predict the high mean nor the fat tail of the histogram of model anomalies. We perform several statistical tests which exclude that microlensing can explain the observed flux-ratio anomalies (although Kolmogorov–Smirnov, which is less sensitive to the tail of the distributions, is not always conclusive). Thus, microlensing cannot statistically explain the bulk of flux-ratio anomalies, and models may explore different alternatives to try to reduce them. In particular, we propose to complement photometric observations with accurate flux ratios of the broad emission lines obtained from integral field spectroscopy to check and, ideally, constrain lens models.Grants PID2020-118687
GBC33 and PID2020-118687GB-C31, financed by MCIN/AEI/10.13039/501100011033Projects FQM-108, P20_00334, and A-FQM-510-UGR20/FEDER, financed by Junta de AndalucíaANID Fondecyt Regular #1231418Centro
de Astrofísica de Valparaís
Constraints on the Abundance of Primordial Black Holes from X-Ray Quasar Microlensing Observations: Substellar to Planetary Mass Range
We thank the anonymous referee for the valuable comments that helped improve this paper. This research was supported by the Spanish projects PID2020-118687GB-C33, PID2020-118687GB-C32 and PID2020-118687GB-C31 financed by MCIN/AEI/10.13039/501100011033. J.J.V. is also supported by projects FQM-108, P20_00334 and A-FQM-510-UGR20/FEDER financed by Junta de Andalucía. J.A.M. is also supported by the Generalitat Valenciana with the project of excellence Prometeo/2020/085. A.E.G. thanks the support from grant FPI-SO from the Spanish MINECO (research project SEV-2015-0548-17-4 and predoctoral contract BES-2017-082319) and acknowledges support from ANID Fondecyt Postdoctorado with grant No. 3230554.We use X-ray observations of quasar microlensing (sensitive to smaller compact objects than in the optical) to study the possible presence of a population of low mass black holes (BHs; from ∼10−3 M ⊙ to 10−1 M ⊙) in lens galaxies. We compare these observations with microlensing magnification simulations of a mixed population of stars and BHs plus a smooth matter component. We estimate the individual mass fractions of both stars and BHs for three different BH masses in the range of substellar to planetary masses. Our Bayesian analysis indicates that the contribution of BHs is negligible in the substellar mass range but that a population of BHs of planetary mass (M ≲ 10−3 M ⊙) could pass unnoticed to X-ray microlensing. We provide new upper limits to the contribution of BHs to the fraction of dark matter based on both, the quasar microlensing data in the X-ray band, and our previous estimates in the optical of intermediate-mass BHs with an additional upper limit at M = 3M ⊙MCIN/AEI/10.13039/501100011033: PID2020-118687GB-C33, PID2020-118687GB-C32, PID2020-118687GB-C31Junta de Andalucía FQM-108, P20_00334, A-FQM-510-UGR20/FEDERGeneralitat Valenciana Prometeo/2020/085Spanish MINECO FPI-SO: SEV-2015-0548-17-4, BES-2017-082319ANID Fondecyt Postdoctorado 323055
The multiphase starburst-driven galactic wind in NGC 5394
We present a detailed study of the neutral and ionized gas phases in the galactic wind for the nearby starburst galaxy NGC 5394 based on new integral field spectroscopy obtained with the INTEGRAL fibre system at the William Herschel Telescope. The neutral gas phase in the wind is detected via the interstellar Na I D doublet absorption. After a careful removal of the stellar contribution to these lines, a significant amount of neutral gas (∼10^7 M_⊙) is detected in a central region of ∼1.75 kpc size. This neutral gas is blueshifted by ∼165 km s^−1 with respect to the underlying galaxy. The mass outflow of neutral gas is comparable to the star formation rate of the host galaxy. Simultaneously, several emission lines (Hα, [N II], [S II]) are also analysed looking for the ionized warm phase counterpart of the wind. A careful kinematic decomposition of the line profiles reveals the presence of a secondary, broader, kinematic component. This component is found roughly in the same region where the Na I D absorption is detected. It presents higher [N II]/Hα and [S II]/Hα line ratios than the narrow component at the same locations, indicative of contamination by shock ionization. This secondary component also presents blueshifted velocities, although smaller than those measured for the neutral gas, averaging to ∼−30 km s^−1. The mass and mass outflow rate of the wind is dominated by the neutral gas, of which a small fraction might be able to escape the gravitational potential of the host galaxy. The observations in this system can be readily understood within a bipolar gas flow scenario
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