arXiv: Astrophysics of Galaxies最新文献_第4页

Quadruply-imaged quasars: some general features 四重成像类星体:一些一般特征

arXiv: Astrophysics of Galaxies Pub Date : 2020-11-26 DOI: 10.5303/JKAS.2020.53.6.149

P. Tuan-Anh, T. T. Thai, N. Tuan, P. Darriulat, P. Diep, D. Hoai, N. B. Ngoc, P. T. Nhung, N. T. Phuong

引用次数: 0

Blandford–Znajek jets in galaxy formation simulations: method and implementation 星系形成模拟中的Blandford-Znajek喷流:方法和实现

arXiv: Astrophysics of Galaxies Pub Date : 2020-11-20 DOI: 10.1093/mnras/stab804

Rosie Y Talbot, M. Bourne, D. Sijacki

{"title":"Blandford–Znajek jets in galaxy formation simulations: method and implementation","authors":"Rosie Y Talbot, M. Bourne, D. Sijacki","doi":"10.1093/mnras/stab804","DOIUrl":"https://doi.org/10.1093/mnras/stab804","url":null,"abstract":"Jets launched by active galactic nuclei (AGN) are believed to play a significant role in shaping the properties of galaxies and provide an energetically viable mechanism through which galaxies can become quenched. Here we present a novel AGN feedback model, which we have incorporated into the AREPO code, that evolves the black hole mass and spin as the accretion flow proceeds through a thin $alpha$-disc which we self-consistently couple to a Blandford-Znajek jet. We apply our model to the central region of a typical radio-loud Seyfert galaxy embedded in a hot circumgalactic medium (CGM). We find that jets launched into high pressure environments thermalise efficiently due to the formation of recollimation shocks and the vigorous instabilities that these shocks excite increase the efficiency of the mixing of CGM and jet material. The beams of more overpressured jets, however, are not as readily disrupted by instabilities so the majority of the momentum flux at the jet base is retained out to the head, where the jet terminates in a reverse shock. All jets entrain a significant amount of cold circumnuclear disc material which, while energetically insignificant, dominates the lobe mass together with the hot, entrained CGM material. The jet power evolves significantly due to effective self-regulation by the black hole, fed by secularly-driven, intermittent mass flows. The direction of jets launched directly into the circumnuclear disc changes considerably due to effective Bardeen-Petterson torquing. Interestingly, these jets obliterate the innermost regions of the disc and drive large-scale, multi-phase, turbulent, bipolar outflows.","PeriodicalId":8452,"journal":{"name":"arXiv: Astrophysics of Galaxies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"74813415","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 12

Completeness of the Gaia-verse III: using hidden states to infer gaps, detection efficiencies, and the scanning law from the DR2 light curves Gaia-verse III的完备性:利用隐藏状态从DR2光曲线推断间隙、检测效率和扫描规律

arXiv: Astrophysics of Galaxies Pub Date : 2020-11-20 DOI: 10.1093/mnras/staa3791

D. Boubert, A. Everall, J. Fraser, A. Gration, B. Holl

{"title":"Completeness of the Gaia-verse III: using hidden states to infer gaps, detection efficiencies, and the scanning law from the DR2 light curves","authors":"D. Boubert, A. Everall, J. Fraser, A. Gration, B. Holl","doi":"10.1093/mnras/staa3791","DOIUrl":"https://doi.org/10.1093/mnras/staa3791","url":null,"abstract":"The completeness of the Gaia catalogues heavily depends on the status of that space telescope through time. Stars are only published with each of the astrometric, photometric and spectroscopic data products if they are detected a minimum number of times. If there is a gap in scientific operations, a drop in the detection efficiency or Gaia deviates from the commanded scanning law, then stars will miss out on potential detections and thus be less likely to make it into the Gaia catalogues. We lay the groundwork to retrospectively ascertain the status of Gaia throughout the mission from the tens of individual measurements of the billions of stars, by developing novel methodologies to infer both the orientation and angular velocity of Gaia through time and gaps and efficiency drops in the detections. We have applied these methodologies to the Gaia DR2 variable star epoch photometry -- which are the only publicly available Gaia time-series at the present time -- and make the results publicly available. We accompany these results with a new Python package scanninglaw (https://github.com/gaiaverse/scanninglaw) that you can use to easily predict Gaia observation times and detection probabilities for arbitrary locations on the sky.","PeriodicalId":8452,"journal":{"name":"arXiv: Astrophysics of Galaxies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81654407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 1

Detection of H2O and OH+ in z > 3 hot dust-obscured galaxies z > 3热尘埃遮蔽星系中H2O和OH+的探测

arXiv: Astrophysics of Galaxies Pub Date : 2020-11-19 DOI: 10.1051/0004-6361/202037888

F. Stanley, K. Knudsen, S. Aalto, L. Fan, N. Falstad, E. Humphreys

{"title":"Detection of H2O and OH+ in z > 3 hot dust-obscured galaxies","authors":"F. Stanley, K. Knudsen, S. Aalto, L. Fan, N. Falstad, E. Humphreys","doi":"10.1051/0004-6361/202037888","DOIUrl":"https://doi.org/10.1051/0004-6361/202037888","url":null,"abstract":"In this paper we present the detection of H2O and OH+ emission in z>3 hot dust-obscured galaxies (Hot DOGs). Using ALMA Band-6 observations of two Hot DOGs, we have detected H2O(2_02-1_11) in W0149+2350, and H2O(3_12-3_03) and the multiplet OH+(1_1-0_1) in W0410-0913. We find that both sources have luminous H2O emission with line luminosities of L_H2O > 2.2x10^8 Lsol and L_H2O = 8.7x10^8 Lsol for W0149+2350 and W0410-0913, respectively. The H2O line profiles are similar to those seen for the neighbouring CO(9-8) line, with linewidths of FWHM ~ 800-1000 km/s. However, the H2O emission seems to be more compact than the CO(9-8). OH+ is detected in emission for W0410-0913, with a FWHM=1000km/s and a line luminosity of L_OH+ = 6.92x10^8 Lsol. The ratio of the observed H2O line luminosity over the IR luminosity, for both Hot DOGs, is consistent with previously observed star forming galaxies and AGN. The H2O/CO line ratio of both Hot DOGs and the OH+/H2O line ratio of W0410-0913 are comparable to those of luminous AGN in the literature. The bright H2O(2_02-1_11), and H2O(3_12-3_03) emission lines are likely due to the combined high star formation levels and luminous AGN in these sources. The presence of OH+ in emission, and the agreement of the observed line ratios of the Hot DOGs with luminous AGN in the literature, would suggest that the AGN emission is dominating the radiative output of these galaxies. However, followup multi-transition observations are needed to better constrain the properties of these systems.","PeriodicalId":8452,"journal":{"name":"arXiv: Astrophysics of Galaxies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80062164","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

The properties of Polycyclic Aromatic Hydrocarbons in galaxies: constraints on PAH sizes, charge and radiation fields 星系中多环芳烃的性质:对多环芳烃大小、电荷和辐射场的限制

arXiv: Astrophysics of Galaxies Pub Date : 2020-11-19 DOI: 10.1093/MNRAS/STAB959

D. Rigopoulou, M. Barale, D. Clary, X. Shan, A. Alonso-Herrero, I. García-Bernete, L. Hunt, B. Kerkeni, M. Pereira-Santaella, P. Roche

{"title":"The properties of Polycyclic Aromatic Hydrocarbons in galaxies: constraints on PAH sizes, charge and radiation fields","authors":"D. Rigopoulou, M. Barale, D. Clary, X. Shan, A. Alonso-Herrero, I. García-Bernete, L. Hunt, B. Kerkeni, M. Pereira-Santaella, P. Roche","doi":"10.1093/MNRAS/STAB959","DOIUrl":"https://doi.org/10.1093/MNRAS/STAB959","url":null,"abstract":"Based on theoretical spectra computed using Density Functional Theory we study the properties of Polycyclic Aromatic Hydrocarbons (PAH). In particular using bin-average spectra of PAH molecules with varying number of carbons we investigate how the intensity of the mid-infrared emission bands, 3.3, 6.2, 7.7 and 11.3 microns, respond to changes in the number of carbons, charge of the molecule, and the hardness of the radiation field that impinges the molecule. We confirm that the 6.2/7.7 band ratio is a good predictor for the size of the PAH molecule (based on the number of carbons present). We also investigate the efficacy of the 11.3/3.3 ratio to trace the size of PAH molecules and note the dependence of this ratio on the hardness of the radiation field. While the ratio can potentially also be used to trace PAH molecular size, a better understanding of the impact of the underlying radiation field on the 3.3 microns feature and the effect of the extinction on the ratio should be evaluated. The newly developed diagnostics are compared to band ratios measured in a variety of galaxies observed with the Infrared Spectrograph on board the Spitzer Space Telescope. We demonstrate that the band ratios can be used to probe the conditions of the interstellar medium in galaxies and differentiate between environments encountered in normal star forming galaxies and Active Galactic Nuclei. Our work highlights the immense potential that PAH observations with the James Webb Space Telescope will have on our understanding of the PAH emission itself and of the physical conditions in galaxies near and far.","PeriodicalId":8452,"journal":{"name":"arXiv: Astrophysics of Galaxies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91008978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Breaking beta: a comparison of mass modelling methods for spherical systems 打破beta:球面系统质量建模方法的比较

arXiv: Astrophysics of Galaxies Pub Date : 2020-11-18 DOI: 10.1093/mnras/staa3663

J. Read, G. Mamon, E. Vasiliev, E. Vasiliev, E. Vasiliev, Laura L. Watkins, Laura L. Watkins, Laura L. Watkins, M. Walker, J. P. narrubia, M. Wilkinson, W. Dehnen, W. Dehnen, Payel Das, Payel Das

{"title":"Breaking beta: a comparison of mass modelling methods for spherical systems","authors":"J. Read, G. Mamon, E. Vasiliev, E. Vasiliev, E. Vasiliev, Laura L. Watkins, Laura L. Watkins, Laura L. Watkins, M. Walker, J. P. narrubia, M. Wilkinson, W. Dehnen, W. Dehnen, Payel Das, Payel Das","doi":"10.1093/mnras/staa3663","DOIUrl":"https://doi.org/10.1093/mnras/staa3663","url":null,"abstract":"We apply four different mass modelling methods to a suite of publicly available mock data for spherical stellar systems. We focus on the recovery of the density and velocity anisotropy as a function of radius, using either line-of-sight velocity data only, or adding proper motion data. All methods perform well on isotropic and tangentially anisotropic mock data, recovering the density and velocity anisotropy within their 95% confidence intervals over the radial range 0.25 < R/Rhalf < 4, where Rhalf is the half light radius. However, radially-anisotropic mocks are more challenging. For line-of-sight data alone, only methods that use information about the shape of the velocity distribution function are able to break the degeneracy between the density profile and the velocity anisotropy to obtain an unbiased estimate of both. This shape information can be obtained through directly fitting a global phase space distribution function, by using higher order 'Virial Shape Parameters', or by assuming a Gaussian velocity distribution function locally, but projecting it self-consistently along the line of sight. Including proper motion data yields further improvements, and in this case, all methods give a good recovery of both the radial density and velocity anisotropy profiles.","PeriodicalId":8452,"journal":{"name":"arXiv: Astrophysics of Galaxies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78697601","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 13

Multifrequency study of a double–double radio galaxy J0028+0035 双双射电星系J0028+0035的多频研究

arXiv: Astrophysics of Galaxies Pub Date : 2020-11-18 DOI: 10.1093/mnras/staa3632

A. Marecki, M. Jamrozy, J. Machalski, U. Pajdosz-Śmierciak

引用次数: 3

A survey of CH2DOH towards starless and pre-stellar cores in the Taurus molecular cloud CH2DOH对金牛座分子云无恒星和前恒星核心的观测

arXiv: Astrophysics of Galaxies Pub Date : 2020-11-17 DOI: 10.1093/mnras/staa3649

Hannah Ambrose, Y. Shirley, S. Scibelli

{"title":"A survey of CH2DOH towards starless and pre-stellar cores in the Taurus molecular cloud","authors":"Hannah Ambrose, Y. Shirley, S. Scibelli","doi":"10.1093/mnras/staa3649","DOIUrl":"https://doi.org/10.1093/mnras/staa3649","url":null,"abstract":"Recent observations indicate that organic molecules are prevalent towards starless and prestellar cores. Deuteration of these molecules has not been well-studied during the starless phase. Published observations of singly-deuterated methanol, CH$_2$DOH, have only been observed in a couple of well-studied, dense and evolved prestellar cores (e.g. L1544, L183). Since the formation of gas-phase methanol during this cold phase is believed to occur via desorption from the icy grain surfaces, observations of CH$_2$DOH may be useful as a probe of the deuterium fraction in the ice mantles of dust grains. We present a systematic survey of CH$_2$DOH towards 12 starless and prestellar cores in the B10 region of the Taurus Molecular Cloud. Nine of the twelve cores are detected with [CH$_2$DOH]/[CH$_3$OH] ranging from $< 0.04$ to $0.23^{+0.12}_{-0.06}$ with a median value of $0.11$. Sources not detected tend to have larger virial parameters and larger methanol linewidths than detected sources. The results of this survey indicate that deuterium fractionation of organic molecules, such as methanol, during the starless phase may be more easily detectable than previously thought.","PeriodicalId":8452,"journal":{"name":"arXiv: Astrophysics of Galaxies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89891864","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 8

Galactic 26Al traces metal loss through hot chimneys 银河26Al通过热烟囱追踪金属的损失

arXiv: Astrophysics of Galaxies Pub Date : 2020-11-17 DOI: 10.1093/mnras/staa3612

M. Krause, D. Rodgers-Lee, J. Dale, R. Diehl, C. Kobayashi

{"title":"Galactic 26Al traces metal loss through hot chimneys","authors":"M. Krause, D. Rodgers-Lee, J. Dale, R. Diehl, C. Kobayashi","doi":"10.1093/mnras/staa3612","DOIUrl":"https://doi.org/10.1093/mnras/staa3612","url":null,"abstract":"Radioactive 26Al is an excellent tracer for metal ejection in the Milky Way, and can provide a direct constraint on the modelling of supernova feedback in galaxy evolution. Gamma-ray observations of the 26Al decay line have found high velocities and hence require a significant fraction of the Galactic 26Al in the hot component. At the same time, meteoritic data combined with simulation results suggest that a significant amount of 26Al makes its way into stars before decay. We investigated the distribution into hot and cold channels with a simulation of a Milky-Way-like galaxy with massive-star feedback in superbubbles and with ejecta traced by 26Al. About 30-40 per cent of the ejecta remain hot, with typical cooling times of the order Gyr. 26Al traces the footpoints of a chimney-fed outflow that mixes metals turbulently into the halo of the model galaxy on a scale of at least 50 kpc. The rest diffuses into cold gas with temperatures less than about 10,000 K, and may therefore be quickly available for star formation. We discuss the robustness of the result by comparison to a simulation with a different global flow pattern. The branching ratio into hot and cold components is comparable to that of longer term average results from chemical evolution modelling of galaxies, clusters and the intracluster medium.","PeriodicalId":8452,"journal":{"name":"arXiv: Astrophysics of Galaxies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79255804","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 7

On the precision of full-spectrum fitting of simple stellar populations – II. The dependence on star cluster mass in the wavelength range 0.3–5.0 µm 简单恒星居群全光谱拟合的精度——ⅱ。波长范围0.3 ~ 5.0µm与星团质量的关系

arXiv: Astrophysics of Galaxies Pub Date : 2020-11-16 DOI: 10.1093/mnras/staa3617

P. Goudfrooij, Randa Asa’d

{"title":"On the precision of full-spectrum fitting of simple stellar populations – II. The dependence on star cluster mass in the wavelength range 0.3–5.0 µm","authors":"P. Goudfrooij, Randa Asa’d","doi":"10.1093/mnras/staa3617","DOIUrl":"https://doi.org/10.1093/mnras/staa3617","url":null,"abstract":"In this second paper of a series on the accuracy and precision of the determination of age and metallicity of simple stellar populations (SSPs) by means of the full spectrum fitting technique, we study the influence of star cluster mass through stochastic fluctuations of the number of stars near the top of the stellar mass function, which dominate the flux in certain wavelength regimes depending on the age. We consider SSP models based on the Padova isochrones, spanning the age range 7.0 $leq$ log (age/yr) $leq$ 10.1. Simulated spectra of star clusters in the mass range $10^4 leq M/M_{odot} < 10^6$ are compared with SSP model spectra to determine best-fit ages and metallicities using a full-spectrum fitting routine in four wavelength regimes: the blue optical (0.35-0.70 $mu$m), the red optical (0.6-1.0 $mu$m), the near-IR (1.0-2.5 $mu$m), and the mid-IR (2.5-5.0 $mu$m). We compare the power of each wavelength regime in terms of both the overall precision of age and metallicity determination, and of its dependence on cluster mass. We also study the relevance of spectral resolution in this context by utilizing two different spectral libraries (BaSeL and BT-Settl). We highlight the power of the mid-IR regime in terms of identifying young massive clusters in dusty star forming regions in external galaxies. The spectra of the simulated star clusters and SSPs are made available online to enable follow-up studies by the community.","PeriodicalId":8452,"journal":{"name":"arXiv: Astrophysics of Galaxies","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79764546","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3