New Astronomy Reviews最新文献

{"title":"Synthesis of radioactive elements in novae and supernovae and their use as a diagnostic tool","authors":"J. Isern ,&nbsp;M. Hernanz ,&nbsp;E. Bravo ,&nbsp;S. Grebenev ,&nbsp;P. Jean ,&nbsp;M. Renaud ,&nbsp;T. Siegert ,&nbsp;J. Vink","doi":"10.1016/j.newar.2020.101606","DOIUrl":"10.1016/j.newar.2020.101606","url":null,"abstract":"<div><p><span>Novae and </span>supernovae<span><span> play a key role in many fields of Astrophysics and Cosmology. Despite their importance, an accurate description of which objects explode and why and how they explode is still lacking. One of the main characteristics of such explosions is that they are the main suppliers of newly synthesized chemical elements in the Galaxy. Since some of these isotopes are radioactive, it is possible to use the corresponding gamma-rays as a diagnostic tool of the explosion thanks to their independence on the thermal state of the debris. The drawback is the poor sensitivity of detectors in the MeV energy domain. As a consequence, the radioactive lines have only been detected in one core collapse supernova (SN 1987A), one </span>Type Ia supernova<span> (SN 2014J), and one supernova remnant (Cas A). Nevertheless these observations have provided and are providing important information about the explosion mechanisms. Unfortunately, novae are still eluding detection. These results emphasize the necessity to place as soon as possible a new instrument in orbit with enough sensitivity to noticeably enlarge the sample of detected events.</span></span></p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"92 ","pages":"Article 101606"},"PeriodicalIF":6.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2020.101606","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"78982582","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Steady-state nucleosynthesis throughout the Galaxy","authors":"Roland Diehl ,&nbsp;Martin G.H. Krause ,&nbsp;Karsten Kretschmer ,&nbsp;Michael Lang ,&nbsp;Moritz M.M. Pleintinger ,&nbsp;Thomas Siegert ,&nbsp;Wei Wang ,&nbsp;Laurent Bouchet ,&nbsp;Pierrick Martin","doi":"10.1016/j.newar.2020.101608","DOIUrl":"https://doi.org/10.1016/j.newar.2020.101608","url":null,"abstract":"&lt;div&gt;&lt;p&gt;The measurement and astrophysical interpretation of characteristic &lt;span&gt;&lt;math&gt;&lt;mi&gt;γ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;-ray lines from nucleosynthesis was one of the prominent science goals of the INTEGRAL mission and in particular its spectrometer SPI. Emission from &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;26&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;Al and from &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;60&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;&lt;span&gt;Fe decay lines, due to their My decay times, originates from accumulated ejecta of nucleosynthesis sources, and appears diffuse in nature. &lt;/span&gt;&lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;26&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;Al and &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;60&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;&lt;span&gt;&lt;span&gt;Fe are believed to originate mostly from massive star clusters. The &lt;/span&gt;radioactive decay &lt;/span&gt;&lt;span&gt;&lt;math&gt;&lt;mi&gt;γ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;&lt;span&gt;-ray observations open an interesting window to trace the fate and flow of nucleosynthesis ejecta, after they have left the immediate sources and their birth sites, and on their path to mix with ambient interstellar gas. The &lt;/span&gt;&lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;26&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;&lt;span&gt;Al emission image obtained with INTEGRAL confirms earlier findings of clumpiness and an extent along the entire plane of the Galaxy, supporting its origin from massive-star groups. INTEGRAL spectroscopy resolved the line and found Doppler broadenings and systematic shifts with longitude, originating from large-scale galactic rotation. But an excess velocity of  200 km s&lt;/span&gt;&lt;sup&gt;−1&lt;/sup&gt; suggests that &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;26&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;&lt;span&gt;&lt;span&gt;Al decays preferentially within large superbubbles that extend in forward directions between &lt;/span&gt;spiral arms. The detection of &lt;/span&gt;&lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;26&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;&lt;span&gt;Al line emission from the nearby Orion clusters in the Eridanus superbubble supports this interpretation. Positrons from &lt;/span&gt;&lt;span&gt;&lt;math&gt;&lt;mi&gt;β&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;&lt;sup&gt;+&lt;/sup&gt; decays of &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;26&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;&lt;span&gt;Al and other nucleosynthesis ejecta have been found to not explain the morphology of positron annihilation &lt;/span&gt;&lt;span&gt;&lt;math&gt;&lt;mi&gt;γ&lt;/mi&gt;&lt;/math&gt;&lt;/span&gt;-rays at 511 keV that have been measured by INTEGRAL. The &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;60&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;Fe signal measured by INTEGRAL is diffuse but too weak for an imaging interpretation, an origin from point-like/concentrated sources is excluded. The &lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;26&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;Al /&lt;span&gt;&lt;math&gt;&lt;msup&gt;&lt;mrow&gt;&lt;/mrow&gt;&lt;mrow&gt;&lt;mn&gt;60&lt;/mn&gt;&lt;mspace&gt;&lt;/mspace&gt;&lt;/mrow&gt;&lt;/msup&gt;&lt;/math&gt;&lt;/span&gt;&lt;span&gt;Fe ratio is constrained to a ra","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"92 ","pages":"Article 101608"},"PeriodicalIF":6.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2020.101608","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91743177","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Numerical simulations of jets","authors":"S. Komissarov, O. Porth","doi":"10.1016/J.NEWAR.2021.101610","DOIUrl":"https://doi.org/10.1016/J.NEWAR.2021.101610","url":null,"abstract":"","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"8 1","pages":"101610"},"PeriodicalIF":6.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84769501","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Gamma-ray burst jets in supernovae","authors":"Alessandra Corsi ,&nbsp;Davide Lazzati","doi":"10.1016/j.newar.2021.101614","DOIUrl":"10.1016/j.newar.2021.101614","url":null,"abstract":"<div><p>We review the current observational status and theoretical interpretations for the class of broad lines type Ic supernovae<span><span>. They are characterized by fast photospheric expansion and lack of H and He absorption. They have a larger than normal energy budget, suggesting that they are powered or, at least, augmented by a central engine, like a magnetar or an accreting black hole. There appears therefore to be a link between these </span>supernovae and long-duration gamma-ray bursts. However, its nature has not been satisfactorily demystified.</span></p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"92 ","pages":"Article 101614"},"PeriodicalIF":6.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2021.101614","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"72530633","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"15 years of galactic surveys and hard X-ray background measurements","authors":"Roman A. Krivonos ,&nbsp;Antony J. Bird ,&nbsp;Eugene M. Churazov ,&nbsp;John A. Tomsick ,&nbsp;Angela Bazzano ,&nbsp;Volker Beckmann ,&nbsp;Guillaume Bélanger ,&nbsp;Arash Bodaghee ,&nbsp;Sylvain Chaty ,&nbsp;Erik Kuulkers ,&nbsp;Alexander Lutovinov ,&nbsp;Angela Malizia ,&nbsp;Nicola Masetti ,&nbsp;Ilya A. Mereminskiy ,&nbsp;Rashid Sunyaev ,&nbsp;Sergey S. Tsygankov ,&nbsp;Pietro Ubertini ,&nbsp;Christoph Winkler","doi":"10.1016/j.newar.2021.101612","DOIUrl":"10.1016/j.newar.2021.101612","url":null,"abstract":"<div><p>The <em>INTEGRAL</em> hard X-ray surveys have proven to be of fundamental importance. <em>INTEGRAL</em><span><span><span> has mapped the Galactic plane with its large field of view and excellent sensitivity. Such hard X-ray snapshots of the whole </span>Milky Way on a time scale of a year are beyond the capabilities of past and current narrow-FOV </span>grazing incidence X-ray telescopes. By expanding the </span><em>INTEGRAL</em> X-ray survey into shorter timescales, a productive search for transient X-ray emitters was made possible. In more than fifteen years of operation, the <em>INTEGRAL</em> observatory has given us a sharper view of the hard X-ray sky, and provided the triggers for many follow-up campaigns from radio frequencies to gamma-rays. In addition to conducting a census of hard X-ray sources across the entire sky, <em>INTEGRAL</em> has carried out, through Earth occultation manoeuvres, unique observations of the large-scale cosmic X-ray background, which will without question be included in the annals of X-ray astronomy as one of the mission’s most salient contribution to our understanding of the hard X-ray sky.</p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"92 ","pages":"Article 101612"},"PeriodicalIF":6.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2021.101612","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"107318268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Multi-messenger astronomy with INTEGRAL","authors":"Carlo Ferrigno ,&nbsp;Volodymyr Savchenko ,&nbsp;Alexis Coleiro ,&nbsp;Francesca Panessa ,&nbsp;Angela Bazzano ,&nbsp;Enrico Bozzo ,&nbsp;Jérôme Chenevez ,&nbsp;Albert Domingo ,&nbsp;Maeve Doyle ,&nbsp;Andrea Goldwurm ,&nbsp;Diego Götz ,&nbsp;Elisabeth Jourdain ,&nbsp;Andreas von Kienlin ,&nbsp;Erik Kuulkers ,&nbsp;Sandro Mereghetti ,&nbsp;Antonio Martin-Carrillo ,&nbsp;Lorenzo Natalucci ,&nbsp;Francesca Onori ,&nbsp;James Rodi ,&nbsp;Jean-Pierre Roques ,&nbsp;Pietro Ubertini","doi":"10.1016/j.newar.2020.101595","DOIUrl":"10.1016/j.newar.2020.101595","url":null,"abstract":"<div><p>At the time of defining the science objectives of the INTernational Gamma-Ray Astrophysics Laboratory (INTEGRAL), such a rapid and spectacular development of multi-messenger astronomy could not have been predicted, with new impulsive phenomena becoming accessible through different channels. Neutrino telescopes have routinely detected energetic neutrino events coming from unknown cosmic sources since 2013. Gravitational wave detectors opened a novel window on the sky in 2015 with the detection of the merging of two black holes and in 2017 with the merging of two neutron stars, followed by signals in the full electromagnetic range. Finally, since 2007, radio telescopes detected extremely intense and short burst of radio waves, known as Fast Radio Bursts (FRBs) whose origin is for most cases extragalactic, but enigmatic. The exceptionally robust and versatile design of the INTEGRAL mission has allowed researchers to exploit data collected not only with the pointed instruments, but also with the active cosmic-ray shields of the main instruments to detect impulses of gamma-rays in coincidence with unpredictable phenomena. The full-sky coverage, mostly unocculted by the Earth, the large effective area, the stable background, and the high duty cycle (85%) put INTEGRAL in a privileged position to give a major contribution to multi-messenger astronomy. In this review, we describe how INTEGRAL has provided upper limits on the gamma-ray emission from black-hole binary mergers, detected a short gamma-ray burst in coincidence with a binary neutron star merger, contributed to define the spectral energy distribution of a blazar associated with a neutrino event, set upper limits on impulsive and steady gamma-ray emission from cosmological FRBs, and detected a magnetar flare associated with fast radio bursting emission.</p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"92 ","pages":"Article 101595"},"PeriodicalIF":6.0,"publicationDate":"2021-06-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2020.101595","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89101982","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"物理与天体物理","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The INTEGRAL view of the pulsating hard X-ray sky: from accreting and transitional millisecond pulsars to rotation-powered pulsars and magnetars","authors":"A. Papitto ,&nbsp;M. Falanga ,&nbsp;W. Hermsen ,&nbsp;S. Mereghetti ,&nbsp;L. Kuiper ,&nbsp;J. Poutanen ,&nbsp;E. Bozzo ,&nbsp;F. Ambrosino ,&nbsp;F. Coti Zelati ,&nbsp;V. De Falco ,&nbsp;D. de Martino ,&nbsp;T. Di Salvo ,&nbsp;P. Esposito ,&nbsp;C. Ferrigno ,&nbsp;M. Forot ,&nbsp;D. Götz ,&nbsp;C. Gouiffes ,&nbsp;R. Iaria ,&nbsp;P. Laurent ,&nbsp;J. Li ,&nbsp;D.F. Torres","doi":"10.1016/j.newar.2020.101544","DOIUrl":"10.1016/j.newar.2020.101544","url":null,"abstract":"<div><p><span><span><span><span>In the last 25 years a new generation of X-ray satellites imparted a significant leap forward in our knowledge of X-ray pulsars. The discovery of accreting and transitional millisecond pulsars proved that </span>disk accretion<span> can spin up a neutron star to a very high rotation speed. The detection of MeV-GeV pulsed emission from a few hundreds of rotation-powered pulsars probed </span></span>particle acceleration in the outer </span>magnetosphere<span>, or even beyond. Also, a population of two dozens of magnetars has emerged. </span></span><em>INTEGRAL</em> played a central role to achieve these results by providing instruments with high temporal resolution up to the hard X-ray/soft, <em>γ</em><span>-ray band and a large field of view imager with good angular resolution to spot hard X-ray transients. In this article we review the main contributions by </span><em>INTEGRAL</em> to our understanding of the pulsating hard X-ray sky, such as the discovery and characterization of several accreting and transitional millisecond pulsars, the generation of the first catalog of hard X-ray/soft <em>γ</em>-ray rotation-powered pulsars, the detection of polarization in the hard X-ray emission from the Crab pulsar, and the discovery of persistent hard X-ray emission from several magnetars.</p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"91 ","pages":"Article 101544"},"PeriodicalIF":6.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2020.101544","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79735482","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"INTEGRAL View on cataclysmic variables and symbiotic binaries","authors":"Alexander Lutovinov ,&nbsp;Valery Suleimanov ,&nbsp;Gerardo Juan Manuel Luna ,&nbsp;Sergey Sazonov ,&nbsp;Domitilla de Martino ,&nbsp;Lorenzo Ducci ,&nbsp;Victor Doroshenko ,&nbsp;Maurizio Falanga","doi":"10.1016/j.newar.2020.101547","DOIUrl":"10.1016/j.newar.2020.101547","url":null,"abstract":"<div><p><span>Accreting white dwarfs (WDs) constitute a significant fraction of the hard X-ray sources detected by the </span><em>INTEGRAL</em><span><span> observatory. Most of them are magnetic Cataclysmic Variables (CVs) of the intermediate polar (IP) and polar types, but the contribution of the Nova-likes systems and the systems with optically thin boundary layers, </span>Dwarf Novae<span> (DNs) and Symbiotic Binaries (or Symbiotic Stars, SySs) in quiescence is also not negligible. Here we present a short review of the results obtained from the observations of cataclysmic variables and symbiotic binaries by </span></span><em>INTEGRAL</em><span>. The highlight results include the significant increase of the known IP population, determination of the WD mass for a significant fraction of IPs, the establishment of the luminosity function of magnetic CVs, and uncovering origin of the Galactic ridge X-ray emission which appears to largely be associated with hard emission from magnetic CVs.</span></p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"91 ","pages":"Article 101547"},"PeriodicalIF":6.0,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2020.101547","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90196245","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"Steady-state nucleosynthesis throughout the Galaxy","authors":"R. Diehl, M. Krause, K. Kretschmer, M. Lang, Moritz M. M. Pleintinger, T. Siegert, Wei Wang, L. Bouchet, Pierrick Martin","doi":"10.1016/j.newar.2020.101608","DOIUrl":"https://doi.org/10.1016/j.newar.2020.101608","url":null,"abstract":"","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"30 1","pages":""},"PeriodicalIF":6.0,"publicationDate":"2020-11-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86966033","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}

{"title":"OB Associations and their origins","authors":"Nicholas J. Wright","doi":"10.1016/j.newar.2020.101549","DOIUrl":"10.1016/j.newar.2020.101549","url":null,"abstract":"<div><p><span><span>OB associations are unbound groups of young stars made prominent by their bright OB members, and have long been thought to be the expanded remnants of dense star clusters. They have been important in astrophysics for over a century thanks to their luminous </span>massive stars<span>, though their low-mass members have not been well studied until the last couple of decades. This has changed thanks to data from X-ray observations, spectroscopic surveys and astrometry from </span></span><em>Gaia</em><span> that allows their full stellar content to be identified and their dynamics to be studied, which in turn is leading to changes in our understanding of these systems and their origins, with the old picture of Blaauw (1964a) now being superseded. It is clear now that OB associations have considerably more substructure than once envisioned, both spatially, kinematically and temporally. These changes have implications for the star formation<span><span> process, the formation and evolution of planetary systems, and the build-up of </span>stellar populations across galaxies.</span></span></p></div>","PeriodicalId":19718,"journal":{"name":"New Astronomy Reviews","volume":"90 ","pages":"Article 101549"},"PeriodicalIF":6.0,"publicationDate":"2020-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://sci-hub-pdf.com/10.1016/j.newar.2020.101549","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80323867","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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}