Pub Date : 2023-10-01DOI: 10.3847/2041-8213/acfcad
Oliver J. Roberts, Matthew G. Baring, Daniela Huppenkothen, Chryssa Kouveliotou, Ersin Göğüş, Yuki Kaneko, Lin Lin, Alexander J. van der Horst, George Younes
Abstract Magnetars are young neutron stars powered by the strongest magnetic fields in the Universe (10 13–15 G). Their transient X-ray emission usually manifests as short (a few hundred milliseconds), bright, energetic (∼10 40–41 erg) X-ray bursts. Since its discovery in 2014, SGR J1935+2154 has become one of the most prolific magnetars, exhibiting very active bursting episodes and other fascinating events, such as pulse timing antiglitches and fast radio bursts. Here we present evidence for possible 42 Hz (24 ms) quasiperiodic oscillations in the ν F ν spectrum peak energy ( E p ) identified in a unique burst detected with the Fermi Gamma-ray Burst Monitor in 2022 January. While quasiperiodic oscillations have been previously reported in the intensity of magnetar burst light curves, quasiperiodic oscillations in E p have not. We also find an additional event from the same outburst that appears to exhibit a similar character in E p , albeit of lower statistical quality. For these two exceptional transients, such E p oscillations can be explained by magnetospheric density and pressure perturbations. For burst-emitting plasma consisting purely of e + e − pairs, these acoustic modes propagate along a highly magnetized flux tube of length up to around L ∼ 130 neutron star radii, with L being lower if ions are present in the emission zone. Detailed time-resolved analyses of other magnetar bursts are encouraged to evaluate the rarity of these events and their underlying mechanisms.
{"title":"Quasiperiodic Peak Energy Oscillations in X-Ray Bursts from SGR J1935+2154","authors":"Oliver J. Roberts, Matthew G. Baring, Daniela Huppenkothen, Chryssa Kouveliotou, Ersin Göğüş, Yuki Kaneko, Lin Lin, Alexander J. van der Horst, George Younes","doi":"10.3847/2041-8213/acfcad","DOIUrl":"https://doi.org/10.3847/2041-8213/acfcad","url":null,"abstract":"Abstract Magnetars are young neutron stars powered by the strongest magnetic fields in the Universe (10 13–15 G). Their transient X-ray emission usually manifests as short (a few hundred milliseconds), bright, energetic (∼10 40–41 erg) X-ray bursts. Since its discovery in 2014, SGR J1935+2154 has become one of the most prolific magnetars, exhibiting very active bursting episodes and other fascinating events, such as pulse timing antiglitches and fast radio bursts. Here we present evidence for possible 42 Hz (24 ms) quasiperiodic oscillations in the ν F ν spectrum peak energy ( E p ) identified in a unique burst detected with the Fermi Gamma-ray Burst Monitor in 2022 January. While quasiperiodic oscillations have been previously reported in the intensity of magnetar burst light curves, quasiperiodic oscillations in E p have not. We also find an additional event from the same outburst that appears to exhibit a similar character in E p , albeit of lower statistical quality. For these two exceptional transients, such E p oscillations can be explained by magnetospheric density and pressure perturbations. For burst-emitting plasma consisting purely of e + e − pairs, these acoustic modes propagate along a highly magnetized flux tube of length up to around L ∼ 130 neutron star radii, with L being lower if ions are present in the emission zone. Detailed time-resolved analyses of other magnetar bursts are encouraged to evaluate the rarity of these events and their underlying mechanisms.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135761226","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2023-10-01DOI: 10.3847/2041-8213/acff5e
Fabio Pacucci, Yueying Ni, Abraham Loeb
Abstract A recent study found dynamical evidence of a supermassive black hole of ∼3 × 10 6 M ⊙ at the center of Leo I, the most distant dwarf spheroidal galaxy of the Milky Way. This black hole, comparable in mass to the Milky Way’s Sgr A*, places the system >2 orders of magnitude above the standard M • – M ⋆ relation. We investigate the possibility, from a dynamical standpoint, that Leo I’s stellar system was originally much more massive and, thus, closer to the relation. Extreme tidal disruption from one or two close passages within the Milky Way’s virial radius could have removed most of its stellar mass. A simple analytical model suggests that the progenitor of Leo I could have experienced a mass loss in the range 32%–57% from a single pericenter passage, depending on the stellar velocity dispersion estimate. This mass-loss percentage increases to the range 66%–78% if the pericenter occurs at the minimum distance allowed by current orbital reconstructions. Detailed N -body simulations show that the mass loss could reach ∼90% with up to two passages, again with pericenter distances compatible with the minimum value allowed by Gaia data. Despite very significant uncertainties in the properties of Leo I, we reproduce its current position and velocity dispersion, as well as the final stellar mass enclosed in 1 kpc (∼5 × 10 6 M ⊙ ) within a factor <2. The most recent tidal stream is directed along our line of sight toward Leo I, making it difficult to detect. Evidence from this extreme tidal disruption event could be present in current Gaia data in the form of extended tidal streams.
{"title":"Extreme Tidal Stripping May Explain the Overmassive Black Hole in Leo I: A Proof of Concept","authors":"Fabio Pacucci, Yueying Ni, Abraham Loeb","doi":"10.3847/2041-8213/acff5e","DOIUrl":"https://doi.org/10.3847/2041-8213/acff5e","url":null,"abstract":"Abstract A recent study found dynamical evidence of a supermassive black hole of ∼3 × 10 6 M ⊙ at the center of Leo I, the most distant dwarf spheroidal galaxy of the Milky Way. This black hole, comparable in mass to the Milky Way’s Sgr A*, places the system >2 orders of magnitude above the standard M • – M ⋆ relation. We investigate the possibility, from a dynamical standpoint, that Leo I’s stellar system was originally much more massive and, thus, closer to the relation. Extreme tidal disruption from one or two close passages within the Milky Way’s virial radius could have removed most of its stellar mass. A simple analytical model suggests that the progenitor of Leo I could have experienced a mass loss in the range 32%–57% from a single pericenter passage, depending on the stellar velocity dispersion estimate. This mass-loss percentage increases to the range 66%–78% if the pericenter occurs at the minimum distance allowed by current orbital reconstructions. Detailed N -body simulations show that the mass loss could reach ∼90% with up to two passages, again with pericenter distances compatible with the minimum value allowed by Gaia data. Despite very significant uncertainties in the properties of Leo I, we reproduce its current position and velocity dispersion, as well as the final stellar mass enclosed in 1 kpc (∼5 × 10 6 M ⊙ ) within a factor <2. The most recent tidal stream is directed along our line of sight toward Leo I, making it difficult to detect. Evidence from this extreme tidal disruption event could be present in current Gaia data in the form of extended tidal streams.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"131 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135810972","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2023-10-01DOI: 10.3847/2041-8213/acfe71
Luis A. Zapata, Manuel Fernández-López, Silvia Leurini, Estrella Guzmán Ccolque, Skretas, I. M., Luis F. Rodríguez, Aina, Palau, Karl M. Menten, Friedrich, Wyrowski
Abstract In the last years there has been a substantial increase in the number of the reported massive and luminous star-forming regions with related explosive outflows thanks to the superb sensitivity and angular resolution provided by the new radio, infrared, and optical facilities. Here, we report one more explosive outflow related with the massive and bright star-forming region IRAS 12326−6245 using Band 6 sensitive and high-angular-resolution (∼0.″2) Atacama Large Millimeter/Submillimeter Array observations. We find over 10 molecular and collimated well-defined streamers, with Hubble–Lemaitre–like expansion motions, and pointing right to the center of a dusty and molecular shell (reported for the first time here) localized in the northern part of the UC H ii region known as G301.1A. The estimated kinematic age and energy for the explosion are ∼700 yr and 10 48 erg, respectively. Taking into account the recently reported explosive outflows together with IRAS 12326−6245, we estimate an event rate of once every 90 yr in our Galaxy, similar to the formation rate of massive stars.
{"title":"One, Two, Three ... An Explosive Outflow in IRAS 12326-6245 Revealed by ALMA","authors":"Luis A. Zapata, Manuel Fernández-López, Silvia Leurini, Estrella Guzmán Ccolque, Skretas, I. M., Luis F. Rodríguez, Aina, Palau, Karl M. Menten, Friedrich, Wyrowski","doi":"10.3847/2041-8213/acfe71","DOIUrl":"https://doi.org/10.3847/2041-8213/acfe71","url":null,"abstract":"Abstract In the last years there has been a substantial increase in the number of the reported massive and luminous star-forming regions with related explosive outflows thanks to the superb sensitivity and angular resolution provided by the new radio, infrared, and optical facilities. Here, we report one more explosive outflow related with the massive and bright star-forming region IRAS 12326−6245 using Band 6 sensitive and high-angular-resolution (∼0.″2) Atacama Large Millimeter/Submillimeter Array observations. We find over 10 molecular and collimated well-defined streamers, with Hubble–Lemaitre–like expansion motions, and pointing right to the center of a dusty and molecular shell (reported for the first time here) localized in the northern part of the UC H ii region known as G301.1A. The estimated kinematic age and energy for the explosion are ∼700 yr and 10 48 erg, respectively. Taking into account the recently reported explosive outflows together with IRAS 12326−6245, we estimate an event rate of once every 90 yr in our Galaxy, similar to the formation rate of massive stars.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"42 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135762041","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2023-10-01DOI: 10.3847/2041-8213/acfdae
Elias R. Most, Alexander A. Philippov
Abstract The presence of magnetic fields in the late inspiral of black hole–neutron star binaries could lead to potentially detectable electromagnetic precursor transients. Using general-relativistic force-free electrodynamics simulations, we investigate premerger interactions of the common magnetosphere of black hole–neutron star systems. We demonstrate that these systems can feature copious electromagnetic flaring activity, which we find depends on the magnetic field orientation but not on black hole spin. Due to interactions with the surrounding magnetosphere, these flares could lead to fast-radio-burst-like transients and X-ray emission, with EM≲1041B*/1012G2ergs−1 as an upper bound on the luminosity, where B * is the magnetic field strength on the surface of the neutron star.
在黑洞-中子星双星的后期吸气中磁场的存在可能导致潜在的可探测的电磁前体瞬变。利用广义相对论的无力电动力学模拟，我们研究了黑洞-中子星系统共同磁层的合并前相互作用。我们证明了这些系统可以具有丰富的电磁耀斑活动，我们发现这取决于磁场方向，而不是黑洞自旋。由于与周围磁层的相互作用，这些耀斑可能导致类似快速射电暴的瞬态和x射线发射，亮度的上限为EM > 10 41 B * / 10 12 G 2 erg s−1，其中B *是中子星表面的磁场强度。
{"title":"Electromagnetic Precursors to Black Hole–Neutron Star Gravitational Wave Events: Flares and Reconnection-powered Fast Radio Transients from the Late Inspiral","authors":"Elias R. Most, Alexander A. Philippov","doi":"10.3847/2041-8213/acfdae","DOIUrl":"https://doi.org/10.3847/2041-8213/acfdae","url":null,"abstract":"Abstract The presence of magnetic fields in the late inspiral of black hole–neutron star binaries could lead to potentially detectable electromagnetic precursor transients. Using general-relativistic force-free electrodynamics simulations, we investigate premerger interactions of the common magnetosphere of black hole–neutron star systems. We demonstrate that these systems can feature copious electromagnetic flaring activity, which we find depends on the magnetic field orientation but not on black hole spin. Due to interactions with the surrounding magnetosphere, these flares could lead to fast-radio-burst-like transients and X-ray emission, with <?CDATA ${{ mathcal L }}_{mathrm{EM}}lesssim {10}^{41}{left({B}_{* }/{10}^{12},{rm{G}}right)}^{2},mathrm{erg},{{rm{s}}}^{-1}$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:msub> <mml:mrow> <mml:mi mathvariant=\"italic\"></mml:mi> </mml:mrow> <mml:mrow> <mml:mi>EM</mml:mi> </mml:mrow> </mml:msub> <mml:mo>≲</mml:mo> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>41</mml:mn> </mml:mrow> </mml:msup> <mml:msup> <mml:mrow> <mml:mfenced close=\")\" open=\"(\"> <mml:mrow> <mml:msub> <mml:mrow> <mml:mi>B</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>*</mml:mo> </mml:mrow> </mml:msub> <mml:mrow> <mml:mo stretchy=\"true\">/</mml:mo> </mml:mrow> <mml:msup> <mml:mrow> <mml:mn>10</mml:mn> </mml:mrow> <mml:mrow> <mml:mn>12</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width=\"0.25em\" /> <mml:mi mathvariant=\"normal\">G</mml:mi> </mml:mrow> </mml:mfenced> </mml:mrow> <mml:mrow> <mml:mn>2</mml:mn> </mml:mrow> </mml:msup> <mml:mspace width=\"0.25em\" /> <mml:mi>erg</mml:mi> <mml:mspace width=\"0.25em\" /> <mml:msup> <mml:mrow> <mml:mi mathvariant=\"normal\">s</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>−</mml:mo> <mml:mn>1</mml:mn> </mml:mrow> </mml:msup> </mml:math> as an upper bound on the luminosity, where B * is the magnetic field strength on the surface of the neutron star.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"196 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135762861","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2023-10-01DOI: 10.3847/2041-8213/acf769
Adam G. Riess, Gagandeep S. Anand, Wenlong Yuan, Stefano Casertano, Andrew Dolphin, Lucas M. Macri, Louise Breuval, Dan Scolnic, Marshall Perrin, Richard I. Anderson
Abstract High-resolution James Webb Space Telescope (JWST) observations can test confusion-limited Hubble Space Telescope (HST) observations for a photometric bias that could affect extragalactic Cepheids and the determination of the Hubble constant. We present JWST NIRCAM observations in two epochs and three filters of >320 Cepheids in NGC 4258 (which has a 1.5% maser-based geometric distance) and in NGC 5584 (host of SN Ia 2007af), near the median distance of the SH0ES HST SN Ia host sample and with the best leverage among them to detect such a bias. JWST provides far superior source separation from line-of-sight companions than HST in the near-infrared to largely negate confusion or crowding noise at these wavelengths, where extinction is minimal. The result is a remarkable >2.5× reduction in the dispersion of the Cepheid period–luminosity relations, from 0.45 to 0.17 mag, improving individual Cepheid precision from 20% to 7%. Two-epoch photometry confirmed identifications, tested JWST photometric stability, and constrained Cepheid phases. The P – L relation intercepts are in very good agreement, with differences (JWST−HST) of 0.00 ± 0.03 and 0.02 ± 0.03 mag for NGC 4258 and NGC 5584, respectively. The difference in the determination of H 0 between HST and JWST from these intercepts is 0.02 ± 0.04 mag, insensitive to JWST zero-points or count rate nonlinearity thanks to error cancellation between rungs. We explore a broad range of analysis variants (including passband combinations, phase corrections, measured detector offsets, and crowding levels) indicating robust baseline results. These observations provide the strongest evidence yet that systematic errors in HST Cepheid photometry do not play a significant role in the present Hubble Tension. Upcoming JWST observations of >12 SN Ia hosts should further refine the local measurement of the Hubble constant.
{"title":"Crowded No More: The Accuracy of the Hubble Constant Tested with High-resolution Observations of Cepheids by JWST","authors":"Adam G. Riess, Gagandeep S. Anand, Wenlong Yuan, Stefano Casertano, Andrew Dolphin, Lucas M. Macri, Louise Breuval, Dan Scolnic, Marshall Perrin, Richard I. Anderson","doi":"10.3847/2041-8213/acf769","DOIUrl":"https://doi.org/10.3847/2041-8213/acf769","url":null,"abstract":"Abstract High-resolution James Webb Space Telescope (JWST) observations can test confusion-limited Hubble Space Telescope (HST) observations for a photometric bias that could affect extragalactic Cepheids and the determination of the Hubble constant. We present JWST NIRCAM observations in two epochs and three filters of >320 Cepheids in NGC 4258 (which has a 1.5% maser-based geometric distance) and in NGC 5584 (host of SN Ia 2007af), near the median distance of the SH0ES HST SN Ia host sample and with the best leverage among them to detect such a bias. JWST provides far superior source separation from line-of-sight companions than HST in the near-infrared to largely negate confusion or crowding noise at these wavelengths, where extinction is minimal. The result is a remarkable >2.5× reduction in the dispersion of the Cepheid period–luminosity relations, from 0.45 to 0.17 mag, improving individual Cepheid precision from 20% to 7%. Two-epoch photometry confirmed identifications, tested JWST photometric stability, and constrained Cepheid phases. The P – L relation intercepts are in very good agreement, with differences (JWST−HST) of 0.00 ± 0.03 and 0.02 ± 0.03 mag for NGC 4258 and NGC 5584, respectively. The difference in the determination of H 0 between HST and JWST from these intercepts is 0.02 ± 0.04 mag, insensitive to JWST zero-points or count rate nonlinearity thanks to error cancellation between rungs. We explore a broad range of analysis variants (including passband combinations, phase corrections, measured detector offsets, and crowding levels) indicating robust baseline results. These observations provide the strongest evidence yet that systematic errors in HST Cepheid photometry do not play a significant role in the present Hubble Tension. Upcoming JWST observations of >12 SN Ia hosts should further refine the local measurement of the Hubble constant.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135810074","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2023-10-01DOI: 10.3847/2041-8213/acfedf
Shun-Yi Lan, Xiang-Cun Meng
Abstract A millisecond pulsar (MSP) is an old neutron star (NS) that has accreted material from its companion star, causing it to spin up, which is known as the recycling scenario. During the mass transfer phase, the system manifests itself as an X-ray binary. PSR J1402+13 is an MSP with a spin period of 5.89 ms and a spin period derivative of logṖspin=−16.32 . These properties make it a notable object within the pulsar population, as MSPs typically exhibit low spin period derivatives. In this paper, we aim to explain how an MSP can possess a high spin period derivative by binary evolution. By utilizing the stellar evolution code MESA , we examine the effects of irradiation on the companion star and the propeller effect on the NS during binary evolution. We demonstrate that irradiation can modify the spin period and mass of an MSP, resulting in a higher spin period derivative. These results suggest that the irradiation effect may serve as a key factor in explaining MSPs with high spin period derivatives.
毫秒脉冲星(MSP)是一颗古老的中子星(NS)，它从伴星中吸积物质，导致其旋转，这被称为再循环情景。在传质阶段，系统表现为x射线双星。PSR J1402+13的自旋周期为5.89 ms，自旋周期导数为log P (spin) =−16.32。这些特性使它成为脉冲星群中一个值得注意的对象，因为msp通常表现出低自旋周期导数。在本文中，我们的目的是通过二元演化来解释MSP如何具有高自旋周期导数。利用恒星演化代码MESA，研究了双星演化过程中辐照对伴星的影响和螺旋桨对NS的影响。我们证明了辐照可以改变MSP的自旋周期和质量，从而导致更高的自旋周期导数。这些结果表明，辐照效应可能是解释具有高自旋周期衍生物的MSPs的关键因素。
{"title":"The Effect of Irradiation on the Spin of Millisecond Pulsars","authors":"Shun-Yi Lan, Xiang-Cun Meng","doi":"10.3847/2041-8213/acfedf","DOIUrl":"https://doi.org/10.3847/2041-8213/acfedf","url":null,"abstract":"Abstract A millisecond pulsar (MSP) is an old neutron star (NS) that has accreted material from its companion star, causing it to spin up, which is known as the recycling scenario. During the mass transfer phase, the system manifests itself as an X-ray binary. PSR J1402+13 is an MSP with a spin period of 5.89 ms and a spin period derivative of <?CDATA $mathrm{log}{dot{P}}_{mathrm{spin}}=-16.32$?> <mml:math xmlns:mml=\"http://www.w3.org/1998/Math/MathML\" overflow=\"scroll\"> <mml:mi>log</mml:mi> <mml:msub> <mml:mrow> <mml:mover accent=\"true\"> <mml:mrow> <mml:mi>P</mml:mi> </mml:mrow> <mml:mrow> <mml:mo>̇</mml:mo> </mml:mrow> </mml:mover> </mml:mrow> <mml:mrow> <mml:mi>spin</mml:mi> </mml:mrow> </mml:msub> <mml:mo>=</mml:mo> <mml:mo>−</mml:mo> <mml:mn>16.32</mml:mn> </mml:math> . These properties make it a notable object within the pulsar population, as MSPs typically exhibit low spin period derivatives. In this paper, we aim to explain how an MSP can possess a high spin period derivative by binary evolution. By utilizing the stellar evolution code MESA , we examine the effects of irradiation on the companion star and the propeller effect on the NS during binary evolution. We demonstrate that irradiation can modify the spin period and mass of an MSP, resulting in a higher spin period derivative. These results suggest that the irradiation effect may serve as a key factor in explaining MSPs with high spin period derivatives.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"49 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135706832","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2023-10-01DOI: 10.3847/2041-8213/acff60
V. Vecchiotti, F. L. Villante, G. Pagliaroli
Abstract IceCube collaboration reported the first high-significance observation of the neutrino emission from the Galactic disk. The observed signal can be due to diffuse emission produced by cosmic rays interacting with interstellar gas but can also arise from a population of sources. In this paper, we evaluate both the diffuse and source contribution by taking advantage of gamma-ray observations and/or theoretical considerations. By comparing our expectations with IceCube measurements, we constrain the fraction of Galactic TeV gamma-ray sources (resolved and unresolved) with hadronic nature. In order to be compatible with the IceCube results, this fraction should be small, or the source proton energy cutoff should be well below the cosmic-ray proton knee. In particular, for a cutoff energy equal to 500 TeV, the fraction of hadronic sources should be less than ∼40% corresponding to a cumulative source flux Φ ν ,s ≤ 2.6 × 10 −10 cm −2 s −1 integrated in the 1–100 TeV energy range. This fraction reduces to ∼20% for energy cutoff reaching the cosmic-ray proton knee around 5 PeV.
{"title":"Unveiling the Nature of Galactic TeV Sources with IceCube Results","authors":"V. Vecchiotti, F. L. Villante, G. Pagliaroli","doi":"10.3847/2041-8213/acff60","DOIUrl":"https://doi.org/10.3847/2041-8213/acff60","url":null,"abstract":"Abstract IceCube collaboration reported the first high-significance observation of the neutrino emission from the Galactic disk. The observed signal can be due to diffuse emission produced by cosmic rays interacting with interstellar gas but can also arise from a population of sources. In this paper, we evaluate both the diffuse and source contribution by taking advantage of gamma-ray observations and/or theoretical considerations. By comparing our expectations with IceCube measurements, we constrain the fraction of Galactic TeV gamma-ray sources (resolved and unresolved) with hadronic nature. In order to be compatible with the IceCube results, this fraction should be small, or the source proton energy cutoff should be well below the cosmic-ray proton knee. In particular, for a cutoff energy equal to 500 TeV, the fraction of hadronic sources should be less than ∼40% corresponding to a cumulative source flux Φ ν ,s ≤ 2.6 × 10 −10 cm −2 s −1 integrated in the 1–100 TeV energy range. This fraction reduces to ∼20% for energy cutoff reaching the cosmic-ray proton knee around 5 PeV.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135965107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2023-10-01DOI: 10.3847/2041-8213/acf9a4
K. Azalee Bostroem, Jeniveve Pearson, Manisha Shrestha, David J. Sand, Stefano Valenti, Saurabh W. Jha, Jennifer E. Andrews, Nathan Smith, Giacomo Terreran, Elizabeth Green, Yize 一泽 Dong 董, Michael Lundquist, Joshua Haislip, Emily T. Hoang, Griffin Hosseinzadeh, Daryl Janzen, Jacob E. Jencson, Vladimir Kouprianov, Emmy Paraskeva, Nicolas E. Meza Retamal, Daniel E. Reichart, Iair Arcavi, Alceste Z. Bonanos, Michael W. Coughlin, Ross Dobson, Joseph Farah, Lluís Galbany, Claudia Gutiérrez, Suzanne Hawley, Leslie Hebb, Daichi Hiramatsu, D. Andrew Howell, Takashi Iijima, Ilya Ilyin, Kiran Jhass, Curtis McCully, Sean Moran, Brett M. Morris, Alessandra C. Mura, Tomás E. Müller-Bravo, James Munday, Megan Newsome, Maria Th. Pabst, Paolo Ochner, Estefania Padilla Gonzalez, Andrea Pastorello, Craig Pellegrino, Lara Piscarreta, Aravind P. Ravi, Andrea Reguitti, Laura Salo, József Vinkó, Kellie de Vos, J. C. Wheeler, G. Grant Williams, Samuel Wyatt
Abstract We present the optical spectroscopic evolution of SN 2023ixf seen in subnight cadence spectra from 1.18 to 15 days after explosion. We identify high-ionization emission features, signatures of interaction with material surrounding the progenitor star, that fade over the first 7 days, with rapid evolution between spectra observed within the same night. We compare the emission lines present and their relative strength to those of other supernovae with early interaction, finding a close match to SN 2020pni and SN 2017ahn in the first spectrum and SN 2014G at later epochs. To physically interpret our observations, we compare them to CMFGEN models with confined, dense circumstellar material around a red supergiant (RSG) progenitor from the literature. We find that very few models reproduce the blended N iii ( λλ 4634.0,4640.6)/C iii ( λλ 4647.5,4650.0) emission lines observed in the first few spectra and their rapid disappearance thereafter, making this a unique diagnostic. From the best models, we find a mass-loss rate of 10 −3 –10 −2 M ⊙ yr −1 , which far exceeds the mass-loss rate for any steady wind, especially for an RSG in the initial mass range of the detected progenitor. These mass-loss rates are, however, similar to rates inferred for other supernovae with early circumstellar interaction. Using the phase when the narrow emission features disappear, we calculate an outer dense radius of circumstellar material R CSM,out ≈ 5 × 10 14 cm, and a mean circumstellar material density of ρ = 5.6 × 10 −14 g cm −3 . This is consistent with the lower limit on the outer radius of the circumstellar material we calculate from the peak H α emission flux, R CSM,out ≳ 9 × 10 13 cm.
{"title":"Early Spectroscopy and Dense Circumstellar Medium Interaction in SN 2023ixf","authors":"K. Azalee Bostroem, Jeniveve Pearson, Manisha Shrestha, David J. Sand, Stefano Valenti, Saurabh W. Jha, Jennifer E. Andrews, Nathan Smith, Giacomo Terreran, Elizabeth Green, Yize 一泽 Dong 董, Michael Lundquist, Joshua Haislip, Emily T. Hoang, Griffin Hosseinzadeh, Daryl Janzen, Jacob E. Jencson, Vladimir Kouprianov, Emmy Paraskeva, Nicolas E. Meza Retamal, Daniel E. Reichart, Iair Arcavi, Alceste Z. Bonanos, Michael W. Coughlin, Ross Dobson, Joseph Farah, Lluís Galbany, Claudia Gutiérrez, Suzanne Hawley, Leslie Hebb, Daichi Hiramatsu, D. Andrew Howell, Takashi Iijima, Ilya Ilyin, Kiran Jhass, Curtis McCully, Sean Moran, Brett M. Morris, Alessandra C. Mura, Tomás E. Müller-Bravo, James Munday, Megan Newsome, Maria Th. Pabst, Paolo Ochner, Estefania Padilla Gonzalez, Andrea Pastorello, Craig Pellegrino, Lara Piscarreta, Aravind P. Ravi, Andrea Reguitti, Laura Salo, József Vinkó, Kellie de Vos, J. C. Wheeler, G. Grant Williams, Samuel Wyatt","doi":"10.3847/2041-8213/acf9a4","DOIUrl":"https://doi.org/10.3847/2041-8213/acf9a4","url":null,"abstract":"Abstract We present the optical spectroscopic evolution of SN 2023ixf seen in subnight cadence spectra from 1.18 to 15 days after explosion. We identify high-ionization emission features, signatures of interaction with material surrounding the progenitor star, that fade over the first 7 days, with rapid evolution between spectra observed within the same night. We compare the emission lines present and their relative strength to those of other supernovae with early interaction, finding a close match to SN 2020pni and SN 2017ahn in the first spectrum and SN 2014G at later epochs. To physically interpret our observations, we compare them to CMFGEN models with confined, dense circumstellar material around a red supergiant (RSG) progenitor from the literature. We find that very few models reproduce the blended N iii ( λλ 4634.0,4640.6)/C iii ( λλ 4647.5,4650.0) emission lines observed in the first few spectra and their rapid disappearance thereafter, making this a unique diagnostic. From the best models, we find a mass-loss rate of 10 −3 –10 −2 M ⊙ yr −1 , which far exceeds the mass-loss rate for any steady wind, especially for an RSG in the initial mass range of the detected progenitor. These mass-loss rates are, however, similar to rates inferred for other supernovae with early circumstellar interaction. Using the phase when the narrow emission features disappear, we calculate an outer dense radius of circumstellar material R CSM,out ≈ 5 × 10 14 cm, and a mean circumstellar material density of ρ = 5.6 × 10 −14 g cm −3 . This is consistent with the lower limit on the outer radius of the circumstellar material we calculate from the peak H α emission flux, R CSM,out ≳ 9 × 10 13 cm.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"136117522","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2023-10-01DOI: 10.3847/2041-8213/acf8cb
Wan-Jin Lu, Zhen-Yin Zhao, F. Y. Wang, Z. G. Dai
Abstract Fast radio bursts (FRBs) are energetic millisecond phenomena in the radio band. Polarimetric studies of repeating FRBs indicate that many of these sources occupy extreme and complex magnetoionized environments. Recently, a frequency-dependent depolarization has been discovered in several repeating FRBs. However, the temporal evolution of polarization properties is limited by the burst rate and observational cadence of telescopes. In this Letter, the temporal evolution of depolarization in repeating FRB 20201124A is explored. Using the simultaneous variation of rotation measure and dispersion measure, we also measure the strength of a magnetic field parallel to the line of sight. The strength ranges from a few μ G to 10 3 μ G. In addition, we find that the evolution of depolarization and magnetic field traces the evolution of rotation measure. Our result supports that the variation of depolarization, rotation measure, and the magnetic field are determined by the same complex magnetoionized screen surrounding the FRB source. The derived properties of the screen are consistent with the wind and the decretion disk of a massive star.
{"title":"Temporal Evolution of Depolarization and Magnetic Field of Fast Radio Burst 20201124A","authors":"Wan-Jin Lu, Zhen-Yin Zhao, F. Y. Wang, Z. G. Dai","doi":"10.3847/2041-8213/acf8cb","DOIUrl":"https://doi.org/10.3847/2041-8213/acf8cb","url":null,"abstract":"Abstract Fast radio bursts (FRBs) are energetic millisecond phenomena in the radio band. Polarimetric studies of repeating FRBs indicate that many of these sources occupy extreme and complex magnetoionized environments. Recently, a frequency-dependent depolarization has been discovered in several repeating FRBs. However, the temporal evolution of polarization properties is limited by the burst rate and observational cadence of telescopes. In this Letter, the temporal evolution of depolarization in repeating FRB 20201124A is explored. Using the simultaneous variation of rotation measure and dispersion measure, we also measure the strength of a magnetic field parallel to the line of sight. The strength ranges from a few μ G to 10 3 μ G. In addition, we find that the evolution of depolarization and magnetic field traces the evolution of rotation measure. Our result supports that the variation of depolarization, rotation measure, and the magnetic field are determined by the same complex magnetoionized screen surrounding the FRB source. The derived properties of the screen are consistent with the wind and the decretion disk of a massive star.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"209 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135606675","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
Pub Date : 2023-10-01DOI: 10.3847/2041-8213/acf4fa
Renzhi Su, Minfeng Gu, S. J. Curran, Elizabeth K. Mahony, Ningyu Tang, James R. Allison, Di Li, Ming Zhu, J. N. H. S. Aditya, Hyein Yoon, Zheng Zheng, Zhongzu Wu
Abstract In this letter, we report the discovery of a fast neutral hydrogen outflow in SDSS J145239.38+062738.0, a merging radio galaxy containing an optical type I active galactic nucleus (AGN). This discovery was made through observations conducted by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) using redshifted 21 cm absorption. The outflow exhibits a blueshifted velocity likely up to ∼−1000 km s −1 with respect to the systemic velocity of the host galaxy with an absorption strength of ∼−0.6 mJy beam −1 corresponding to an optical depth of 0.002 at v = −500 km s −1 . The mass outflow rate ranges between 2.8 × 10 −2 and 3.6 M ⊙ yr −1 , implying an energy outflow rate ranging between 4.2 × 10 39 and 9.7 × 10 40 erg s −1 , assuming 100 K < T s < 1000 K. Plausible drivers of the outflow include the starbursts, AGN radiation, and radio jet, the last of which is considered the most likely culprit according to the kinematics. By analyzing the properties of the outflow, AGN, and jet, we find that if the H i outflow is driven by the AGN radiation, the AGN radiation does not seem powerful enough to provide negative feedback, whereas the radio jet shows the potential to provide negative feedback. Our observations contribute another example of a fast outflow detected in neutral hydrogen and demonstrate the capability of FAST in detecting such outflows.
在这封信函中，我们报告了在SDSS J145239.38+062738.0中发现的快速中性氢流出，这是一个合并的射电星系，包含一个光学型I活动星系核(AGN)。这一发现是通过500米口径球面射电望远镜(FAST)使用红移21厘米吸收进行的观测得出的。相对于宿主星系的系统速度，流出物的蓝移速度可能高达~−1000 km s−1，吸收强度为~−0.6 mJy光束−1，对应于v =−500 km s−1时的光学深度为0.002。质量流出率在2.8 × 10−2和3.6 M⊙yr−1之间，这意味着假设100 K <，能量流出率在4.2 × 10 39和9.7 × 10 40 erg s−1之间;这是<1000 K。流出的可能驱动因素包括星暴、AGN辐射和射电喷流，根据运动学，最后一个被认为是最有可能的罪魁祸首。通过分析外流、AGN和喷流的特性，我们发现，如果H i外流是由AGN辐射驱动的，那么AGN辐射似乎不足以提供负反馈，而射电喷流则显示出提供负反馈的潜力。我们的观测提供了在中性氢中检测到快速流出的另一个例子，并证明了fast在检测这种流出方面的能力。
{"title":"FAST Discovery of a Fast Neutral Hydrogen Outflow","authors":"Renzhi Su, Minfeng Gu, S. J. Curran, Elizabeth K. Mahony, Ningyu Tang, James R. Allison, Di Li, Ming Zhu, J. N. H. S. Aditya, Hyein Yoon, Zheng Zheng, Zhongzu Wu","doi":"10.3847/2041-8213/acf4fa","DOIUrl":"https://doi.org/10.3847/2041-8213/acf4fa","url":null,"abstract":"Abstract In this letter, we report the discovery of a fast neutral hydrogen outflow in SDSS J145239.38+062738.0, a merging radio galaxy containing an optical type I active galactic nucleus (AGN). This discovery was made through observations conducted by the Five-hundred-meter Aperture Spherical radio Telescope (FAST) using redshifted 21 cm absorption. The outflow exhibits a blueshifted velocity likely up to ∼−1000 km s −1 with respect to the systemic velocity of the host galaxy with an absorption strength of ∼−0.6 mJy beam −1 corresponding to an optical depth of 0.002 at v = −500 km s −1 . The mass outflow rate ranges between 2.8 × 10 −2 and 3.6 M ⊙ yr −1 , implying an energy outflow rate ranging between 4.2 × 10 39 and 9.7 × 10 40 erg s −1 , assuming 100 K < T s < 1000 K. Plausible drivers of the outflow include the starbursts, AGN radiation, and radio jet, the last of which is considered the most likely culprit according to the kinematics. By analyzing the properties of the outflow, AGN, and jet, we find that if the H i outflow is driven by the AGN radiation, the AGN radiation does not seem powerful enough to provide negative feedback, whereas the radio jet shows the potential to provide negative feedback. Our observations contribute another example of a fast outflow detected in neutral hydrogen and demonstrate the capability of FAST in detecting such outflows.","PeriodicalId":55567,"journal":{"name":"Astrophysical Journal Letters","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135761394","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"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}
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