Publications of the Astronomical Society of Australia最新文献

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Dashing through the cluster: An X-ray to radio view of UGC 10420 undergoing ram-pressure stripping 冲过星系团:UGC 10420正经历撞击压力剥离的x射线到射电图像
IF 6.3 3区 物理与天体物理
Publications of the Astronomical Society of Australia Pub Date : 2023-02-04 DOI: 10.1017/pasa.2023.6
S. Mahajan, K. Singh, J. Tiwari, Somak Raychaudhury
{"title":"Dashing through the cluster: An X-ray to radio view of UGC 10420 undergoing ram-pressure stripping","authors":"S. Mahajan, K. Singh, J. Tiwari, Somak Raychaudhury","doi":"10.1017/pasa.2023.6","DOIUrl":"https://doi.org/10.1017/pasa.2023.6","url":null,"abstract":"Abstract We present multi-wavelength data and analysis, including new FUV AstroSat/UVIT observations of the spiral galaxy UGC 10420 ( \u0000$z=0.032$\u0000 ), a member of the cluster Abell 2199. UGC 10420 is present on the edge of the X-ray emitting region of the cluster at a distance of \u0000${sim} 680$\u0000 kpc from the centre. The far-ultraviolet (FUV) data obtained by the AstroSat mission show intense knots of star formation on the leading edge of the galaxy, accompanied by a tail of the same on the diametrically opposite side. Our analysis shows that the images of the galaxy disc in the optical and mid-infrared are much smaller in size than that in the FUV. While the broadband optical colours of UGC 10420 are typical of a post-starburst galaxy, the star formation rate (SFR) derived from a UV-to-IR spectral energy distribution is at least a factor of nine higher than that expected for a star-forming field galaxy of similar mass at its redshift. A careful removal of the contribution of the diffuse intracluster gas shows that the significant diffuse X-ray emission associated with the interstellar medium of UGC 10420 has a temperature, \u0000$T_X = 0.24^{+0.09}_{-0.06}$\u0000 keV (0.4–2.0 keV) and luminosity, \u0000$L_X = 1.8pm{0.9}times 10^{40}$\u0000 erg s \u0000$^{-1}$\u0000 , which are typical of the X-ray emission from late-type spiral galaxies. Two symmetrically placed X-ray hot spots are observed on either sides of an X-ray weak nucleus. Our analysis favours a scenario where the interaction of a galaxy with the hot intracluster medium of the cluster, perturbs the gas in the galaxy causing starburst in the leading edge of the disc. On the other hand, the turbulence thus developed may also push some of the gas out of the disc. Interactions between the gas ejected from the galaxy and the intracluster medium can then locally trigger star formation in the wake of the galaxy experiencing ram-pressure stripping. Our data however does not rule out the possibility of a flyby encounter with a neighbouring galaxy, although no relevant candidates are observed in the vicinity of UGC 10420.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":"32 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87943312","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
From young to old: The evolutionary path of Pulsar Wind Nebulae 从年轻到年老:脉冲星风星云的演化路径
IF 6.3 3区 物理与天体物理
Publications of the Astronomical Society of Australia Pub Date : 2023-01-30 DOI: 10.1017/pasa.2023.5
B. Olmi, N. Bucciantini
{"title":"From young to old: The evolutionary path of Pulsar Wind Nebulae","authors":"B. Olmi, N. Bucciantini","doi":"10.1017/pasa.2023.5","DOIUrl":"https://doi.org/10.1017/pasa.2023.5","url":null,"abstract":"Abstract Pulsar wind nebulae (PWN) are fascinating systems and archetypal sources for high-energy astrophysics in general. Due to their vicinity, brightness, to the fact that they shine at multi-wavelengths, and especially to their long-living emission at gamma rays, modelling their properties is particularly important for the correct interpretation of the visible Galaxy. A complication in this respect is the variety of properties and morphologies they show at different ages. Here, we discuss the differences among the evolutionary phases of PWN, how they have been modeled in the past and what progresses have been recently made. We approach the discussion from a phenomenological, theoretical (especially numerical) and observational point of view, with particular attention to the most recent results and open questions about the physics of such intriguing sources.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":"1 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90550156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 5
Image-based searches for pulsar candidates using MWA VCS data 基于MWA VCS数据的脉冲星候选星图像搜索
IF 6.3 3区 物理与天体物理
Publications of the Astronomical Society of Australia Pub Date : 2023-01-25 DOI: 10.1017/pasa.2022.59
S. Sett, N. Bhat, M. Sokolowski, E. Lenc
{"title":"Image-based searches for pulsar candidates using MWA VCS data","authors":"S. Sett, N. Bhat, M. Sokolowski, E. Lenc","doi":"10.1017/pasa.2022.59","DOIUrl":"https://doi.org/10.1017/pasa.2022.59","url":null,"abstract":"Abstract Pulsars have been studied extensively over the last few decades and have proven instrumental in exploring a wide variety of physics. Discovering more pulsars emitting at low radio frequencies is crucial to further our understanding of spectral properties and emission mechanisms. The Murchison Widefield Array Voltage Capture System (MWA VCS) has been routinely used to study pulsars at low frequencies and discover new pulsars. The MWA VCS offers the unique opportunity of recording complex voltages from all individual antennas (tiles), which can be off-line beamformed or correlated/imaged at millisecond time resolution. Devising imaged-based methods for finding pulsar candidates, which can be verified in beamformed data, can accelerate the complete process and lead to more pulsar detections. Image-based searches for pulsar candidates can reduce the number of tied-array beams required, increasing compute resource efficiency. Despite a factor of \u0000$sim$\u0000 4 loss in sensitivity, searching for pulsar candidates in images from the MWA VCS, we can explore a larger parameter space, potentially leading to discoveries of pulsars missed by high-frequency surveys such as steep spectrum pulsars, exotic binary systems, or pulsars obscured in high-time resolution time series data by propagation effects. Image-based searches are also essential to probing parts of parameter space inaccessible to traditional beamformed searches with the MWA (e.g. at high dispersion measures). In this paper we describe the innovative approach and capability of dual-processing MWA VCS data, that is forming 1-s visibilities and sky images, finding pulsar candidates in these images, and verifying by forming tied-array beam. We developed and tested image-based methods of finding pulsar candidates, which are based on pulsar properties such as steep spectral index, polarisation and variability. The efficiency of these methodologies has been verified on known pulsars, and the main limitations explained in terms of sensitivity and low-frequency spectral turnover of some pulsars. No candidates were confirmed to be a new pulsar, but this new capability will now be applied to a larger subset of observations to accelerate pulsar discoveries with the MWA and potentially speed up future searches with the SKA-Low.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":"51 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-01-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91207051","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Localisation of gamma-ray bursts from the combined SpIRIT+HERMES-TP/SP nano-satellite constellation 来自SpIRIT+HERMES-TP/SP联合纳米卫星星座的伽马射线暴定位
IF 6.3 3区 物理与天体物理
Publications of the Astronomical Society of Australia Pub Date : 2023-01-24 DOI: 10.1017/pasa.2023.4
M. Thomas, M. Trenti, A. Sanna, R. Campana, G. Ghirlanda, J. Řípa, L. Burderi, F. Fiore, Y. Evangelista, L. Amati, S. Barraclough, K. Auchettl, M. O. del Castillo, A. Chapman, M. Citossi, A. Colagrossi, G. Dilillo, N. Deiosso, E. Demenev, F. Longo, A. Marino, J. McRobbie, R. Mearns, A. Melandri, A. Riggio, T. di Salvo, S. Puccetti, M. Topinka
{"title":"Localisation of gamma-ray bursts from the combined SpIRIT+HERMES-TP/SP nano-satellite constellation","authors":"M. Thomas, M. Trenti, A. Sanna, R. Campana, G. Ghirlanda, J. Řípa, L. Burderi, F. Fiore, Y. Evangelista, L. Amati, S. Barraclough, K. Auchettl, M. O. del Castillo, A. Chapman, M. Citossi, A. Colagrossi, G. Dilillo, N. Deiosso, E. Demenev, F. Longo, A. Marino, J. McRobbie, R. Mearns, A. Melandri, A. Riggio, T. di Salvo, S. Puccetti, M. Topinka","doi":"10.1017/pasa.2023.4","DOIUrl":"https://doi.org/10.1017/pasa.2023.4","url":null,"abstract":"Abstract Multi-messenger observations of the transient sky to detect cosmic explosions and counterparts of gravitational wave mergers critically rely on orbiting wide-FoV telescopes to cover the wide range of wavelengths where atmospheric absorption and emission limit the use of ground facilities. Thanks to continuing technological improvements, miniaturised space instruments operating as distributed-aperture constellations are offering new capabilities for the study of high-energy transients to complement ageing existing satellites. In this paper we characterise the performance of the upcoming joint SpIRIT and HERMES-TP/SP constellation for the localisation of high-energy transients through triangulation of signal arrival times. SpIRIT is an Australian technology and science demonstrator satellite designed to operate in a low-Earth Sun-synchronous Polar orbit that will augment the science operations for the equatorial HERMES-TP/SP constellation. In this work we simulate the improvement to the localisation capabilities of the HERMES-TP/SP constellation when SpIRIT is included in an orbital plane nearly perpendicular (inclination = 97.6°) to the HERMES-TP/SP orbits. For the fraction of GRBs detected by three of the HERMES satellites plus SpIRIT, we find that the combined constellation is capable of localising 60% of long GRBs to within \u0000${sim}30,textrm{deg}^{2}$\u0000 on the sky, and 60% of short GRBs within \u0000${sim}1850,textrm{deg}^{2}$\u0000 ( \u0000$1sigma$\u0000 confidence regions), though it is beyond the scope of this work to characterise or rule out systematic uncertainty of the same order of magnitude. Based purely on statistical GRB localisation capabilities (i.e., excluding systematic uncertainties and sky coverage), these figures for long GRBs are comparable to those reported by the Fermi Gamma Burst Monitor instrument. These localisation statistics represents a reduction of the uncertainty for the burst localisation region for both long and short GRBs by a factor of \u0000${sim}5$\u0000 compared to the HERMES-TP/SP alone. Further improvements by an additional factor of 2 (or 4) can be achieved by launching an additional 4 (or 6) SpIRIT-like satellites into a Polar orbit, respectively, which would both increase the fraction of sky covered by multiple satellite elements, and also enable localisation of \u0000${geq} 60%$\u0000 of long GRBs to within a radius of \u0000${sim}1.5^{circ}$\u0000 (statistical uncertainty) on the sky, clearly demonstrating the value of a distributed all-sky high-energy transient monitor composed of nano-satellites.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":"115 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89177883","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
The transience and persistence of high optical polarisation state in beamed radio quasars 射电类星体中高光偏振态的瞬态和持久性
IF 6.3 3区 物理与天体物理
Publications of the Astronomical Society of Australia Pub Date : 2023-01-15 DOI: 10.1017/pasa.2023.3
K. Chand, Gopal-Krishna, A. Omar, H. Chand, P. Bisht
{"title":"The transience and persistence of high optical polarisation state in beamed radio quasars","authors":"K. Chand, Gopal-Krishna, A. Omar, H. Chand, P. Bisht","doi":"10.1017/pasa.2023.3","DOIUrl":"https://doi.org/10.1017/pasa.2023.3","url":null,"abstract":"Abstract We examine the long-term stability (on decade-like timescales) of optical ‘high polarisation’ (HP) state with \u0000${p_{opt}}$\u0000 \u0000${> 3%}$\u0000 , which commonly occurs in flat-spectrum (i.e., beamed) radio quasars (FSRQs) and is a prominent marker of blazar state. Using this clue, roughly a quarter of the FSRQ population has been reported to undergo HP \u0000$leftrightarrow$\u0000 non-HP state transition on year-like timescales. This work examines the extent to which HP (i.e., blazar) state can endure in a FSRQ, despite these ‘frequent’ state transitions. This is the first attempt to verify, using purely opto-polarimetric data for a much enlarged sample of blazars, the recent curious finding that blazar state in individual quasars persists for at least a few decades, despite its changing/swinging observed fairly commonly on year-like timescales. The present analysis is based on a well-defined sample of 83 radio quasars, extracted from the opto-polarimetric survey RoboPol (2013–2017), for which old opto-polarimetric data taken prior to 1990 could be found in the literature. By a source-wise comparison of these two datasets of the same observable ( \u0000$p_{opt}$\u0000 ), we find that \u0000$sim$\u0000 90% of the 63 quasars found in blazar state in our RoboPol sample, were also observed to be in that state about three decades before. On the other hand, within the RoboPol survey itself, we find that roughly a quarter of the blazars in our sample migrated to the other polarisation state on year-like timescales, by crossing the customary \u0000$p_{opt}$\u0000 = 3% threshold. Evidently, these relatively frequent transitions (in either direction) do not curtail the propensity of a radio quasar to retain its blazar (i.e., HP) state for at least a few decades. The observed transitions/swings of polarisation state are probably manifestation of transient processes, like ejections of synchrotron plasma blobs (VLBI radio knots) from the active nucleus.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":"70 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89379935","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Very long baseline interferometry observations of the high-redshift blazar candidate J0141–5427 高红移耀变体候选者J0141-5427的超长基线干涉测量观测
IF 6.3 3区 物理与天体物理
Publications of the Astronomical Society of Australia Pub Date : 2023-01-11 DOI: 10.1017/pasa.2023.2
K. Gab'anyi, S. Belladitta, S. Frey, G. Orosz, L. Gurvits, K. Rozgonyi, T. An, H. Cao, Z. Paragi, K. Perger
{"title":"Very long baseline interferometry observations of the high-redshift blazar candidate J0141–5427","authors":"K. Gab'anyi, S. Belladitta, S. Frey, G. Orosz, L. Gurvits, K. Rozgonyi, T. An, H. Cao, Z. Paragi, K. Perger","doi":"10.1017/pasa.2023.2","DOIUrl":"https://doi.org/10.1017/pasa.2023.2","url":null,"abstract":"Abstract Active galactic nuclei (AGN) have been observed as far as redshift \u0000$z sim 7$\u0000 . They are crucial in investigating the early Universe as well as the growth of supermassive black holes at their centres. Radio-loud AGN with their jets seen at a small viewing angle are called blazars and show relativistic boosting of their emission. Thus, their apparently brighter jets are easier to detect in the high-redshift Universe. DES J014132.4–542749.9 is a radio-luminous but X-ray weak blazar candidate at \u0000$z = 5$\u0000 . We conducted high-resolution radio interferometric observations of this source with the Australian Long Baseline Array at \u0000$1.7$\u0000 and \u0000$8.5$\u0000 GHz. A single, compact radio-emitting feature was detected at both frequencies with a flat radio spectrum. We derived the milliarcsecond-level accurate position of the object. The frequency dependence of its brightness temperature is similar to that of blazar sources observed at lower redshifts. Based on our observations, we can confirm its blazar nature. We compared its radio properties with those of two other similarly X-ray-weak and radio-bright AGN, and found that they show very different relativistic boosting characteristics.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":"183 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2023-01-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75530332","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
MWA rapid follow-up of gravitational wave transients: Prospects for detecting prompt radio counterparts 引力波瞬态的MWA快速跟踪:探测提示无线电对应物的前景
3区 物理与天体物理
Publications of the Astronomical Society of Australia Pub Date : 2023-01-01 DOI: 10.1017/pasa.2023.49
J. Tian, G. E. Anderson, A. J. Cooper, K. Gourdji, M. Sokolowski, A. Rowlinson, A. Williams, G. Sleap, D. Dobie, D. L. Kaplan, Tara Murphy, S. J. Tingay, F. H. Panther, P. D. Lasky, A. Bahramian, J. C. A. Miller-Jones, C. W. James, B. W. Meyers, S. J. McSweeney, P. J. Hancock
{"title":"MWA rapid follow-up of gravitational wave transients: Prospects for detecting prompt radio counterparts","authors":"J. Tian, G. E. Anderson, A. J. Cooper, K. Gourdji, M. Sokolowski, A. Rowlinson, A. Williams, G. Sleap, D. Dobie, D. L. Kaplan, Tara Murphy, S. J. Tingay, F. H. Panther, P. D. Lasky, A. Bahramian, J. C. A. Miller-Jones, C. W. James, B. W. Meyers, S. J. McSweeney, P. J. Hancock","doi":"10.1017/pasa.2023.49","DOIUrl":"https://doi.org/10.1017/pasa.2023.49","url":null,"abstract":"Abstract We present and evaluate the prospects for detecting coherent radio counterparts to gravitational wave (GW) events using Murchison Widefield Array (MWA) triggered observations. The MWA rapid-response system, combined with its buffering mode ( $sim$ 4 min negative latency), enables us to catch any radio signals produced from seconds prior to hours after a binary neutron star (BNS) merger. The large field of view of the MWA ( $sim$ $1,000,textrm{deg}^2$ at 120 MHz) and its location under the high sensitivity sky region of the LIGO-Virgo-KAGRA (LVK) detector network, forecast a high chance of being on-target for a GW event. We consider three observing configurations for the MWA to follow up GW BNS merger events, including a single dipole per tile, the full array, and four sub-arrays. We then perform a population synthesis of BNS systems to predict the radio detectable fraction of GW events using these configurations. We find that the configuration with four sub-arrays is the best compromise between sky coverage and sensitivity as it is capable of placing meaningful constraints on the radio emission from 12.6% of GW BNS detections. Based on the timescales of four BNS merger coherent radio emission models, we propose an observing strategy that involves triggering the buffering mode to target coherent signals emitted prior to, during or shortly following the merger, which is then followed by continued recording for up to three hours to target later time post-merger emission. We expect MWA to trigger on $sim$ $5-22$ BNS merger events during the LVK O4 observing run, which could potentially result in two detections of predicted coherent emission.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134979975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Lyman-α at Cosmic Noon I: Lyα Spectral Type Selection of z ∼ 2 – 3 Lyman Break Galaxies with Broadband Imaging 宇宙正午I的Lyman-α: z ~ 2 - 3 Lyman断裂星系的Lyα光谱类型选择与宽带成像
3区 物理与天体物理
Publications of the Astronomical Society of Australia Pub Date : 2023-01-01 DOI: 10.1017/pasa.2023.48
Garry Foran, Jeff Cooke, Naveen Reddy, Charles Steidel, Alice Shapley
{"title":"Lyman-<i>α</i> at Cosmic Noon I: Ly<i>α</i> Spectral Type Selection of <i>z</i> ∼ 2 – 3 Lyman Break Galaxies with Broadband Imaging","authors":"Garry Foran, Jeff Cooke, Naveen Reddy, Charles Steidel, Alice Shapley","doi":"10.1017/pasa.2023.48","DOIUrl":"https://doi.org/10.1017/pasa.2023.48","url":null,"abstract":"Abstract High-redshift Lyman break galaxies (LBGs) are efficiently selected in deep images using as few as three broadband filters, and have been shown to have multiple intrinsic and small- to large-scale environmental properties related to Lyman- $alpha$ . In this paper we demonstrate a statistical relationship between net Lyman- $alpha$ equivalent width (net Ly $alpha$ EW) and the optical broadband photometric properties of LBGs at $zsim2$ . We show that LBGs with the strongest net Ly $alpha$ EW in absorption (aLBGs) and strongest net Ly $alpha$ EW in emission (eLBGs) separate into overlapping but discrete distributions in $(U_n-mathcal{R})$ colour and $mathcal{R}$ -band magnitude space, and use this segregation behaviour to determine photometric selection criteria by which sub-samples with a desired Ly $alpha$ spectral type can be selected using data from as few as three broadband optical filters. We propose application of our result to current and future large-area and all-sky photometric surveys that will select hundreds of millions of LBGs across many hundreds to thousands of Mpc, and for which spectroscopic follow-up to obtain Ly $alpha$ spectral information is prohibitive. To this end, we use spectrophotometry of composite spectra derived from a sample of 798 LBGs divided into quartiles on the basis of net Ly $alpha$ EW to calculate selection criteria for the isolation of Ly $alpha$ -absorbing and Ly $alpha$ -emitting populations of $zsim3$ LBGs using ugri broadband photometric data from the Vera Rubin Observatory Legacy Survey of Space and Time (LSST).","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":"152 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135838444","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
DeepGlow: An efficient neural network emulator of physical afterglow models for gamma-ray bursts and gravitational-wave events DeepGlow:一个高效的神经网络仿真器,用于伽马射线暴和引力波事件的物理余辉模型
IF 6.3 3区 物理与天体物理
Publications of the Astronomical Society of Australia Pub Date : 2022-12-21 DOI: 10.1017/pasa.2023.32
O. Boersma, J. van Leeuwen
{"title":"DeepGlow: An efficient neural network emulator of physical afterglow models for gamma-ray bursts and gravitational-wave events","authors":"O. Boersma, J. van Leeuwen","doi":"10.1017/pasa.2023.32","DOIUrl":"https://doi.org/10.1017/pasa.2023.32","url":null,"abstract":"Abstract Gamma-ray bursts (GRBs) and double neutron star merger gravitational-wave events are followed by afterglows that shine from X-rays to radio, and these broadband transients are generally interpreted using analytical models. Such models are relatively fast to execute, and thus easily allow estimates of the energy and geometry parameters of the blast wave, through many trial-and-error model calculations. One problem, however, is that such analytical models do not capture the underlying physical processes as well as more realistic relativistic numerical hydrodynamic (RHD) simulations do. Ideally, those simulations are used for parameter estimation instead, but their computational cost makes this intractable. To this end, we present DeepGlow, a highly efficient neural network architecture trained to emulate a computationally costly RHD-based model of GRB afterglows, to within a few percent accuracy. As a first scientific application, we compare both the emulator and a different analytical model calibrated to RHD simulations, to estimate the parameters of a broadband GRB afterglow. We find consistent results between these two models, and also give further evidence for a stellar wind progenitor environment around this GRB source. DeepGlow fuses simulations that are otherwise too complex to execute over all parameters, to real broadband data of current and future GRB afterglows.","PeriodicalId":20753,"journal":{"name":"Publications of the Astronomical Society of Australia","volume":"2 1","pages":""},"PeriodicalIF":6.3,"publicationDate":"2022-12-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87655127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
CosmoDRAGoN simulations—I. Dynamics and observable signatures of radio jets in cosmological environments CosmoDRAGoN simulations-I。宇宙环境中射电喷流的动力学和可观测特征
IF 6.3 3区 物理与天体物理
Publications of the Astronomical Society of Australia Pub Date : 2022-12-20 DOI: 10.1017/pasa.2023.10
Patrick M Yates-Jones, S. Shabala, C. Power, M. Krause, M. Hardcastle, Elena A. N. Mohd Noh Velastín, G. C. Stewart
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引用次数: 2
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