Pub Date : 2025-01-24DOI: 10.3847/2041-8213/ada554
Tsuyoshi Iizuka, Yuki Hibiya, Satoshi Yoshihara and Takehito Hayakawa
The radioactive decay of short-lived 26Al–26Mg has been used to estimate the timescales over which 26Al was produced in a nearby star and the protosolar disk evolved. The chronology commonly assumes that 26Al was uniformly distributed in the protosolar disk; however, this assumption is challenged by the discordance between the timescales defined by the Al–Mg and assumption-free Pb–Pb chronometers. We find that the 26Al heterogeneity is correlated with the nucleosynthetic stable Ti isotope variation, which can be ascribed to the nonuniform distribution of ejecta from a core-collapse supernova in the disk. We use the Al–Ti isotope correlation to calibrate variable 26Al abundances in Al–Mg dating of early solar system processes. The calibrated Al–Mg chronometer indicates a ≥1 Myr gap between parent body accretion ages of carbonaceous and noncarbonaceous chondrites. We further use the Al–Ti isotope correlation to constrain the timing and location of the supernova explosion, indicating that the explosion occurred at 20–30 pc from the protosolar cloud, 0.94 +0.25/–0.21 Myr before the formation of the oldest solar system solids. Our results imply that the Sun was born in association with a ∼25 Mʘ star.
{"title":"Timescales of Solar System Formation Based on Al–Ti Isotope Correlation by Supernova Ejecta","authors":"Tsuyoshi Iizuka, Yuki Hibiya, Satoshi Yoshihara and Takehito Hayakawa","doi":"10.3847/2041-8213/ada554","DOIUrl":"https://doi.org/10.3847/2041-8213/ada554","url":null,"abstract":"The radioactive decay of short-lived 26Al–26Mg has been used to estimate the timescales over which 26Al was produced in a nearby star and the protosolar disk evolved. The chronology commonly assumes that 26Al was uniformly distributed in the protosolar disk; however, this assumption is challenged by the discordance between the timescales defined by the Al–Mg and assumption-free Pb–Pb chronometers. We find that the 26Al heterogeneity is correlated with the nucleosynthetic stable Ti isotope variation, which can be ascribed to the nonuniform distribution of ejecta from a core-collapse supernova in the disk. We use the Al–Ti isotope correlation to calibrate variable 26Al abundances in Al–Mg dating of early solar system processes. The calibrated Al–Mg chronometer indicates a ≥1 Myr gap between parent body accretion ages of carbonaceous and noncarbonaceous chondrites. We further use the Al–Ti isotope correlation to constrain the timing and location of the supernova explosion, indicating that the explosion occurred at 20–30 pc from the protosolar cloud, 0.94 +0.25/–0.21 Myr before the formation of the oldest solar system solids. Our results imply that the Sun was born in association with a ∼25 Mʘ star.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143027258","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The recent launch of Einstein Probe (EP) in early 2024 opened up a new window onto the transient X-ray sky, allowing for real-time discovery and follow-up of fast X-ray transients (FXRTs). Multiwavelength observations of FXRTs and their counterparts are key to characterize the properties of their outflows and, ultimately, identify their progenitors. Here, we report our long-term radio monitoring of EP 240315A, a long-lasting (∼1000 s) high-redshift (z = 4.9) FXRT associated to gamma-ray burst (GRB) 240315C. Our campaign, carried out with the Australian Telescope Compact Array, followed the transient’s evolution at two different frequencies (5.5 and 9 GHz) for 3 months. In the radio light curves we identify an unusual steep rise at 9 GHz, possibly due to a refreshed reverse shock, and a late-time rapid decay of the radio flux, which we interpret as a jet break due to the outflow collimation. We find that the multiwavelength counterpart of EP 240315A is well described by a model of relativistic jet seen close to its axis, with jet half-opening angle θj ≈ 3° and beaming-corrected total energy E ≃ 4 × 1051 erg, typical of GRBs. These results show that a substantial fraction of FXRTs may be associated to standard GRBs and that sensitive X-ray monitors, such as EP and the proposed HiZ-GUNDAM and Theseus missions, can successfully pinpoint their relativistic outflows up to high redshifts.
{"title":"Long-term Radio Monitoring of the Fast X-Ray Transient EP 240315a: Evidence for a Relativistic Jet","authors":"Roberto Ricci, Eleonora Troja, Yu-Han Yang, Muskan Yadav, Yuan Liu, Hui Sun, Xuefeng Wu, He Gao, Bing Zhang and Weimin Yuan","doi":"10.3847/2041-8213/ad8b3f","DOIUrl":"https://doi.org/10.3847/2041-8213/ad8b3f","url":null,"abstract":"The recent launch of Einstein Probe (EP) in early 2024 opened up a new window onto the transient X-ray sky, allowing for real-time discovery and follow-up of fast X-ray transients (FXRTs). Multiwavelength observations of FXRTs and their counterparts are key to characterize the properties of their outflows and, ultimately, identify their progenitors. Here, we report our long-term radio monitoring of EP 240315A, a long-lasting (∼1000 s) high-redshift (z = 4.9) FXRT associated to gamma-ray burst (GRB) 240315C. Our campaign, carried out with the Australian Telescope Compact Array, followed the transient’s evolution at two different frequencies (5.5 and 9 GHz) for 3 months. In the radio light curves we identify an unusual steep rise at 9 GHz, possibly due to a refreshed reverse shock, and a late-time rapid decay of the radio flux, which we interpret as a jet break due to the outflow collimation. We find that the multiwavelength counterpart of EP 240315A is well described by a model of relativistic jet seen close to its axis, with jet half-opening angle θj ≈ 3° and beaming-corrected total energy E ≃ 4 × 1051 erg, typical of GRBs. These results show that a substantial fraction of FXRTs may be associated to standard GRBs and that sensitive X-ray monitors, such as EP and the proposed HiZ-GUNDAM and Theseus missions, can successfully pinpoint their relativistic outflows up to high redshifts.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"104 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020573","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-22DOI: 10.3847/2041-8213/ad9ead
Samson H. W. Leong, Justin Janquart, Aditya Kumar Sharma, Paul Martens, Parameswaran Ajith and Otto A. Hannuksela
The dense and dynamic environments within active galactic nuclei (AGN) accretion disks may serve as prolific birthplaces for binary black holes (BBHs) and one possible origin for some of the BBHs detected by gravitational-wave (GW) observatories. We show that a considerable fraction of the BBH in AGN disks will be strongly lensed by the central supermassive black hole (SMBH). Thus, the nonobservation of lensed GW signals can be used to constrain the fraction of BBH binaries residing in AGN disks. The nondetection of lensing with current detections will be sufficient to start placing constraints on the fraction of BBHs living within accretion disks near the SMBH. In the next-generation detectors era, with BBH observations and no lensed events, we will be able to rule out most migration traps as dominant birthplaces of BBH mergers; moreover, we will be able to constrain the minimum size of the accretion disk. On the other hand, should AGNs constitute a major formation channel, lensed events from AGNs will become prominent in the future.
{"title":"Constraining Binary Mergers in Active Galactic Nuclei Disks Using the Nonobservation of Lensed Gravitational Waves","authors":"Samson H. W. Leong, Justin Janquart, Aditya Kumar Sharma, Paul Martens, Parameswaran Ajith and Otto A. Hannuksela","doi":"10.3847/2041-8213/ad9ead","DOIUrl":"https://doi.org/10.3847/2041-8213/ad9ead","url":null,"abstract":"The dense and dynamic environments within active galactic nuclei (AGN) accretion disks may serve as prolific birthplaces for binary black holes (BBHs) and one possible origin for some of the BBHs detected by gravitational-wave (GW) observatories. We show that a considerable fraction of the BBH in AGN disks will be strongly lensed by the central supermassive black hole (SMBH). Thus, the nonobservation of lensed GW signals can be used to constrain the fraction of BBH binaries residing in AGN disks. The nondetection of lensing with current detections will be sufficient to start placing constraints on the fraction of BBHs living within accretion disks near the SMBH. In the next-generation detectors era, with BBH observations and no lensed events, we will be able to rule out most migration traps as dominant birthplaces of BBH mergers; moreover, we will be able to constrain the minimum size of the accretion disk. On the other hand, should AGNs constitute a major formation channel, lensed events from AGNs will become prominent in the future.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020576","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-22DOI: 10.3847/2041-8213/ada559
Tian Zhang, Hong Tang, Xiongyao Li, Yuanyun Wen, Bing Mo, Wen Yu, Chuanjiao Zhou and Jianzhong Liu
M-type asteroids are historically thought to be exposed metallic cores of differentiated planets with a composition dominated by pure iron and nickel. However, recent spectral and radar observations reveal an insufficient number of M-type asteroids in the main belt. Here, we report unusual space weathering characteristics associated with a natural metal grain found in Chang'e 5 lunar soil. Microcraters, impact glass, iron whiskers, and unique vesicular rims on the surface of this grain help to explain the unusual properties of some potential M-type asteroids, including low thermal inertia and density. Our findings indicate that space weathering processes, including micrometeorite bombardment and solar wind irradiation, conceal the real surface signatures of M-type asteroids. Furthermore, the presence of He and Ge alloy on the metal grain suggests that M-type asteroids are not only a large metallic Fe and Ni reservoir but also a potential source of noble gases and precious metals.
{"title":"Unusual Space Weathering on a CE-5 Metal Grain Indicates Deceptive Surface Signatures of M-type Asteroids","authors":"Tian Zhang, Hong Tang, Xiongyao Li, Yuanyun Wen, Bing Mo, Wen Yu, Chuanjiao Zhou and Jianzhong Liu","doi":"10.3847/2041-8213/ada559","DOIUrl":"https://doi.org/10.3847/2041-8213/ada559","url":null,"abstract":"M-type asteroids are historically thought to be exposed metallic cores of differentiated planets with a composition dominated by pure iron and nickel. However, recent spectral and radar observations reveal an insufficient number of M-type asteroids in the main belt. Here, we report unusual space weathering characteristics associated with a natural metal grain found in Chang'e 5 lunar soil. Microcraters, impact glass, iron whiskers, and unique vesicular rims on the surface of this grain help to explain the unusual properties of some potential M-type asteroids, including low thermal inertia and density. Our findings indicate that space weathering processes, including micrometeorite bombardment and solar wind irradiation, conceal the real surface signatures of M-type asteroids. Furthermore, the presence of He and Ge alloy on the metal grain suggests that M-type asteroids are not only a large metallic Fe and Ni reservoir but also a potential source of noble gases and precious metals.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"62 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020574","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-22DOI: 10.3847/2041-8213/ada6b7
James Craig Rodi, Dominik Patryk Pacholski, Sandro Mereghetti, Edoardo Arrigoni, Angela Bazzano, Lorenzo Natalucci, Ruben Salvaterra and Pietro Ubertini
We report the results on the short gamma-ray burst GRB 241107A, obtained with the IBIS instrument on board the INTEGRAL satellite. The burst had a duration of about 0.2 s, a fluence of 8 × 10−7 erg cm−2 in the 20 keV–10 MeV range, and a hard spectrum, characterized by a peak energy of 680 keV. The position of GRB 241107A has been precisely determined because it fell inside the imaging field of view of the IBIS coded mask instrument. The presence of the nearby galaxy PGC 86046 in the 3′ radius error region suggests that GRB 241107A might be a giant flare from a magnetar rather than a canonical short gamma-ray burst. For the 4.1 Mpc distance of PGC 86046, the isotropic energy of 1.6 × 1045 erg is in agreement with this hypothesis, which is also supported by the time-resolved spectral properties similar to those of the few other extragalactic magnetars giant flares detected so far.
{"title":"GRB 241107A: A Giant Flare from a Close-by Extragalactic Magnetar?","authors":"James Craig Rodi, Dominik Patryk Pacholski, Sandro Mereghetti, Edoardo Arrigoni, Angela Bazzano, Lorenzo Natalucci, Ruben Salvaterra and Pietro Ubertini","doi":"10.3847/2041-8213/ada6b7","DOIUrl":"https://doi.org/10.3847/2041-8213/ada6b7","url":null,"abstract":"We report the results on the short gamma-ray burst GRB 241107A, obtained with the IBIS instrument on board the INTEGRAL satellite. The burst had a duration of about 0.2 s, a fluence of 8 × 10−7 erg cm−2 in the 20 keV–10 MeV range, and a hard spectrum, characterized by a peak energy of 680 keV. The position of GRB 241107A has been precisely determined because it fell inside the imaging field of view of the IBIS coded mask instrument. The presence of the nearby galaxy PGC 86046 in the 3′ radius error region suggests that GRB 241107A might be a giant flare from a magnetar rather than a canonical short gamma-ray burst. For the 4.1 Mpc distance of PGC 86046, the isotropic energy of 1.6 × 1045 erg is in agreement with this hypothesis, which is also supported by the time-resolved spectral properties similar to those of the few other extragalactic magnetars giant flares detected so far.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020577","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-22DOI: 10.3847/2041-8213/ad9eb5
Sean M. Ressler, Luciano Combi, Bart Ripperda and Elias R. Most
Supermassive binary black holes in galactic centers are potential multimessenger sources in gravitational waves and electromagnetic radiation. To find such objects, isolating unique electromagnetic signatures of their accretion flow is key. With the aid of three-dimensional general-relativistic magnetohydrodynamic simulations that utilize an approximate, semianalytic, superimposed spacetime metric, we identify two such signatures for merging binaries. Both involve magnetic reconnection and are analogous to plasma processes observed in the solar corona. The first, like colliding flux tubes that can cause solar flares, involves colliding jets that form an extended reconnection layer, dissipating magnetic energy and causing the two jets to merge. The second, akin to coronal mass ejection events, involves the accretion of magnetic field lines onto both black holes; these magnetic fields then twist, inflate, and form a trailing current sheet, ultimately reconnecting and driving a hot outflow. We provide estimates for the associated electromagnetic emission for both processes, showing that they likely accelerate electrons to high energies and are promising candidates for continuous, stochastic, and/or quasi-periodic higher-energy electromagnetic emission. We also show that the accretion flows around each black hole can display features associated with the magnetically arrested state. However, simulations with black hole spins misaligned with the orbital plane and simulations with larger Bondi radii saturate at lower values of horizon-penetrating magnetic flux than standard magnetically arrested disks, leading to weaker, intermittent jets owing to feedback from the weak jets or equatorial flux tubes ejected by reconnecting field lines near the horizon.
{"title":"Dual Jet Interaction, Magnetically Arrested Flows, and Flares in Accreting Binary Black Holes","authors":"Sean M. Ressler, Luciano Combi, Bart Ripperda and Elias R. Most","doi":"10.3847/2041-8213/ad9eb5","DOIUrl":"https://doi.org/10.3847/2041-8213/ad9eb5","url":null,"abstract":"Supermassive binary black holes in galactic centers are potential multimessenger sources in gravitational waves and electromagnetic radiation. To find such objects, isolating unique electromagnetic signatures of their accretion flow is key. With the aid of three-dimensional general-relativistic magnetohydrodynamic simulations that utilize an approximate, semianalytic, superimposed spacetime metric, we identify two such signatures for merging binaries. Both involve magnetic reconnection and are analogous to plasma processes observed in the solar corona. The first, like colliding flux tubes that can cause solar flares, involves colliding jets that form an extended reconnection layer, dissipating magnetic energy and causing the two jets to merge. The second, akin to coronal mass ejection events, involves the accretion of magnetic field lines onto both black holes; these magnetic fields then twist, inflate, and form a trailing current sheet, ultimately reconnecting and driving a hot outflow. We provide estimates for the associated electromagnetic emission for both processes, showing that they likely accelerate electrons to high energies and are promising candidates for continuous, stochastic, and/or quasi-periodic higher-energy electromagnetic emission. We also show that the accretion flows around each black hole can display features associated with the magnetically arrested state. However, simulations with black hole spins misaligned with the orbital plane and simulations with larger Bondi radii saturate at lower values of horizon-penetrating magnetic flux than standard magnetically arrested disks, leading to weaker, intermittent jets owing to feedback from the weak jets or equatorial flux tubes ejected by reconnecting field lines near the horizon.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"103 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-21DOI: 10.3847/2041-8213/ada3d1
Sho Shibata and Andre Izidoro
The solar system's planetary architecture has been proposed to be consistent with the terrestrial and giant planets forming from material rings at ∼1 au and ∼5 au, respectively. Here, we show that super-Earths and mini-Neptunes may share a similar formation pathway. In our simulations conducted with a disk α-viscosity of 4 × 10−3, super-Earths accrete from rings of rocky material in the inner disk, growing predominantly via planetesimal accretion. Mini-Neptunes primarily originate from rings located beyond the water snowline, forming via pebble accretion. Our simulations broadly match the period-ratio distribution, the intrasystem size uniformity, and the planet multiplicity distribution of exoplanets. The radius valley constrains the typical total mass available for rocky planet formation to be less than 3–6 M⊕. Our results predict that planets at ∼1 au in systems with close-in super-Earths and mini-Neptunes are predominantly water-rich. Though relatively uncommon, at ∼1% level, such systems might also host rocky Earth-sized planets in the habitable zone that underwent late giant impacts, akin to the Moon-forming event.
{"title":"Formation of Super-Earths and Mini-Neptunes from Rings of Planetesimals","authors":"Sho Shibata and Andre Izidoro","doi":"10.3847/2041-8213/ada3d1","DOIUrl":"https://doi.org/10.3847/2041-8213/ada3d1","url":null,"abstract":"The solar system's planetary architecture has been proposed to be consistent with the terrestrial and giant planets forming from material rings at ∼1 au and ∼5 au, respectively. Here, we show that super-Earths and mini-Neptunes may share a similar formation pathway. In our simulations conducted with a disk α-viscosity of 4 × 10−3, super-Earths accrete from rings of rocky material in the inner disk, growing predominantly via planetesimal accretion. Mini-Neptunes primarily originate from rings located beyond the water snowline, forming via pebble accretion. Our simulations broadly match the period-ratio distribution, the intrasystem size uniformity, and the planet multiplicity distribution of exoplanets. The radius valley constrains the typical total mass available for rocky planet formation to be less than 3–6 M⊕. Our results predict that planets at ∼1 au in systems with close-in super-Earths and mini-Neptunes are predominantly water-rich. Though relatively uncommon, at ∼1% level, such systems might also host rocky Earth-sized planets in the habitable zone that underwent late giant impacts, akin to the Moon-forming event.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"57 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143020596","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-21DOI: 10.3847/2041-8213/ad9de2
T. Eftekhari, Y. Dong, 雨欣 董, W. Fong, V. Shah, S. Simha, B. C. Andersen, S. Andrew, M. Bhardwaj, T. Cassanelli, S. Chatterjee, D. A. Coulter, E. Fonseca, B. M. Gaensler, A. C. Gordon, J. W. T. Hessels, A. L. Ibik, R. C. Joseph, L. A. Kahinga, V. Kaspi, B. Kharel, C. D. Kilpatrick, A. E. Lanman, M. Lazda, C. Leung, C. Liu, L. Mas-Ribas, K. W. Masui, R. Mckinven, J. Mena-Parra, A. A. Miller, K. Nimmo, A. Pandhi, S. S. Patil, A. B. Pearlman, Z. Pleunis, J. X. Prochaska, M. Rafiei-Ravandi, M. Sammons, P. Scholz, K. Shin, K. Smith and I. Stairs
The discovery and localization of FRB 20240209A by the Canadian Hydrogen Intensity Mapping Fast Radio Burst (CHIME/FRB) experiment marks the first repeating FRB localized with the CHIME/FRB Outriggers and adds to the small sample of repeating FRBs with associated host galaxies. Here we present Keck and Gemini observations of the host that reveal a redshift z = 0.1384 ± 0.0004. We perform stellar population modeling to jointly fit the optical through mid-IR data of the host and infer a median stellar mass log(M*/M⊙) = 11.35 ± 0.01 and a mass-weighted stellar population age ~11 Gyr, corresponding to the most massive and oldest FRB host discovered to date. Coupled with a star formation rate <0.31 M⊙ yr−1, the specific star formation rate <10−11.9 yr−1 classifies the host as quiescent. Through surface brightness profile modeling, we determine an elliptical galaxy morphology, marking the host as the first confirmed elliptical FRB host. The discovery of a quiescent early-type host galaxy within a transient class predominantly characterized by late-type star-forming hosts is reminiscent of short-duration gamma-ray bursts, Type Ia supernovae, and ultraluminous X-ray sources. Based on these shared host demographics, coupled with a large offset as demonstrated in our companion Letter, we conclude that preferred sources for FRB 20240209A include magnetars formed through merging binary neutron stars/white dwarfs or the accretion-induced collapse of a white dwarf, or a luminous X-ray binary. Together with FRB 20200120E localized to a globular cluster in M81, our findings provide strong evidence that some fraction of FRBs may arise from a process distinct from the core collapse of massive stars.
{"title":"The Massive and Quiescent Elliptical Host Galaxy of the Repeating Fast Radio Burst FRB 20240209A","authors":"T. Eftekhari, Y. Dong, 雨欣 董, W. Fong, V. Shah, S. Simha, B. C. Andersen, S. Andrew, M. Bhardwaj, T. Cassanelli, S. Chatterjee, D. A. Coulter, E. Fonseca, B. M. Gaensler, A. C. Gordon, J. W. T. Hessels, A. L. Ibik, R. C. Joseph, L. A. Kahinga, V. Kaspi, B. Kharel, C. D. Kilpatrick, A. E. Lanman, M. Lazda, C. Leung, C. Liu, L. Mas-Ribas, K. W. Masui, R. Mckinven, J. Mena-Parra, A. A. Miller, K. Nimmo, A. Pandhi, S. S. Patil, A. B. Pearlman, Z. Pleunis, J. X. Prochaska, M. Rafiei-Ravandi, M. Sammons, P. Scholz, K. Shin, K. Smith and I. Stairs","doi":"10.3847/2041-8213/ad9de2","DOIUrl":"https://doi.org/10.3847/2041-8213/ad9de2","url":null,"abstract":"The discovery and localization of FRB 20240209A by the Canadian Hydrogen Intensity Mapping Fast Radio Burst (CHIME/FRB) experiment marks the first repeating FRB localized with the CHIME/FRB Outriggers and adds to the small sample of repeating FRBs with associated host galaxies. Here we present Keck and Gemini observations of the host that reveal a redshift z = 0.1384 ± 0.0004. We perform stellar population modeling to jointly fit the optical through mid-IR data of the host and infer a median stellar mass log(M*/M⊙) = 11.35 ± 0.01 and a mass-weighted stellar population age ~11 Gyr, corresponding to the most massive and oldest FRB host discovered to date. Coupled with a star formation rate <0.31 M⊙ yr−1, the specific star formation rate <10−11.9 yr−1 classifies the host as quiescent. Through surface brightness profile modeling, we determine an elliptical galaxy morphology, marking the host as the first confirmed elliptical FRB host. The discovery of a quiescent early-type host galaxy within a transient class predominantly characterized by late-type star-forming hosts is reminiscent of short-duration gamma-ray bursts, Type Ia supernovae, and ultraluminous X-ray sources. Based on these shared host demographics, coupled with a large offset as demonstrated in our companion Letter, we conclude that preferred sources for FRB 20240209A include magnetars formed through merging binary neutron stars/white dwarfs or the accretion-induced collapse of a white dwarf, or a luminous X-ray binary. Together with FRB 20200120E localized to a globular cluster in M81, our findings provide strong evidence that some fraction of FRBs may arise from a process distinct from the core collapse of massive stars.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992324","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-21DOI: 10.3847/2041-8213/ad9ddc
Vishwangi Shah, Kaitlyn Shin, Calvin Leung, Wen-fai Fong, Tarraneh Eftekhari, Mandana Amiri, Bridget C. Andersen, Shion Andrew, Mohit Bhardwaj, Charanjot Brar, Tomas Cassanelli, Shami Chatterjee, Alice Curtin, Matt Dobbs, Yuxin Dong, 雨欣 董, Fengqiu Adam Dong, Emmanuel Fonseca, B. M. Gaensler, Mark Halpern, Jason W. T. Hessels, Adaeze L. Ibik, Naman Jain, Ronniy C. Joseph, Jane Kaczmarek, Lordrick A. Kahinga, Victoria M. Kaspi, Bikash Kharel, Tom Landecker, Adam E. Lanman, Mattias Lazda, Robert Main, Lluis Mas-Ribas, Kiyoshi W. Masui, Ryan Mckinven, Juan Mena-Parra, Bradley W. Meyers, Daniele Michilli, Kenzie Nimmo, Ayush Pandhi, Swarali Shivraj Patil, Aaron B. Pearlman, Ziggy Pleunis, J. Xavier Prochaska, Masoud Rafiei-Ravandi, Mawson Sammons, Ketan R. Sand, Paul Scholz, Kendrick Smith and Ingrid Stairs
We report the discovery of the repeating fast radio burst (FRB) source FRB 20240209A using the Canadian Hydrogen Intensity Mapping Experiment (CHIME)/FRB telescope. We detected 22 bursts from this repeater between 2024 February and July, 6 of which were also recorded at the Outrigger station k’niʔatn k’l⌣stk’masqt (KKO). The multiple very long baseline interferometry localizations using the 66 km long CHIME–KKO baseline, each with a different baseline vector orientation due to the repeater’s high decl. of ∼86°, enabled the combined localization region to be constrained to 1″ × 2″. We present deep Gemini optical observations that, combined with the FRB localization, enabled a robust association of FRB 20240209A to the outskirts of a luminous galaxy (P(O∣x) = 0.99; L ≈ 5.3 × 1010L⊙). FRB 20240209A has a projected physical offset of 40 ± 5 kpc from the center of its host galaxy, making it the FRB with the largest host galaxy offset to date. When normalized by the host galaxy size, the offset of FRB 20240209A (5.1 Reff) is comparable to that of FRB 20200120E (5.7 Reff), the only FRB source known to originate in a globular cluster. We consider several explanations for the large offset, including a progenitor that was kicked from the host galaxy or in situ formation in a low-luminosity satellite galaxy of the putative host, but find the most plausible scenario to be a globular cluster origin. This, coupled with the quiescent, elliptical nature of the host as demonstrated in our companion Letter, provides strong evidence for a delayed formation channel for the progenitor of the FRB source.
{"title":"A Repeating Fast Radio Burst Source in the Outskirts of a Quiescent Galaxy","authors":"Vishwangi Shah, Kaitlyn Shin, Calvin Leung, Wen-fai Fong, Tarraneh Eftekhari, Mandana Amiri, Bridget C. Andersen, Shion Andrew, Mohit Bhardwaj, Charanjot Brar, Tomas Cassanelli, Shami Chatterjee, Alice Curtin, Matt Dobbs, Yuxin Dong, 雨欣 董, Fengqiu Adam Dong, Emmanuel Fonseca, B. M. Gaensler, Mark Halpern, Jason W. T. Hessels, Adaeze L. Ibik, Naman Jain, Ronniy C. Joseph, Jane Kaczmarek, Lordrick A. Kahinga, Victoria M. Kaspi, Bikash Kharel, Tom Landecker, Adam E. Lanman, Mattias Lazda, Robert Main, Lluis Mas-Ribas, Kiyoshi W. Masui, Ryan Mckinven, Juan Mena-Parra, Bradley W. Meyers, Daniele Michilli, Kenzie Nimmo, Ayush Pandhi, Swarali Shivraj Patil, Aaron B. Pearlman, Ziggy Pleunis, J. Xavier Prochaska, Masoud Rafiei-Ravandi, Mawson Sammons, Ketan R. Sand, Paul Scholz, Kendrick Smith and Ingrid Stairs","doi":"10.3847/2041-8213/ad9ddc","DOIUrl":"https://doi.org/10.3847/2041-8213/ad9ddc","url":null,"abstract":"We report the discovery of the repeating fast radio burst (FRB) source FRB 20240209A using the Canadian Hydrogen Intensity Mapping Experiment (CHIME)/FRB telescope. We detected 22 bursts from this repeater between 2024 February and July, 6 of which were also recorded at the Outrigger station k’niʔatn k’l⌣stk’masqt (KKO). The multiple very long baseline interferometry localizations using the 66 km long CHIME–KKO baseline, each with a different baseline vector orientation due to the repeater’s high decl. of ∼86°, enabled the combined localization region to be constrained to 1″ × 2″. We present deep Gemini optical observations that, combined with the FRB localization, enabled a robust association of FRB 20240209A to the outskirts of a luminous galaxy (P(O∣x) = 0.99; L ≈ 5.3 × 1010L⊙). FRB 20240209A has a projected physical offset of 40 ± 5 kpc from the center of its host galaxy, making it the FRB with the largest host galaxy offset to date. When normalized by the host galaxy size, the offset of FRB 20240209A (5.1 Reff) is comparable to that of FRB 20200120E (5.7 Reff), the only FRB source known to originate in a globular cluster. We consider several explanations for the large offset, including a progenitor that was kicked from the host galaxy or in situ formation in a low-luminosity satellite galaxy of the putative host, but find the most plausible scenario to be a globular cluster origin. This, coupled with the quiescent, elliptical nature of the host as demonstrated in our companion Letter, provides strong evidence for a delayed formation channel for the progenitor of the FRB source.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142992323","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-20DOI: 10.3847/2041-8213/ada3d2
Sebastiano D. von Fellenberg, Tamojeet Roychowdhury, Joseph M. Michail, Zach Sumners, Grace Sanger-Johnson, Giovanni G. Fazio, Daryl Haggard, Joseph L. Hora, Alexander Philippov, Bart Ripperda, Howard A. Smith, S. P. Willner, Gunther Witzel, Shuo Zhang, Eric E. Becklin, Geoffrey C. Bower, Sunil Chandra, Tuan Do, Macarena Garcia Marin, Mark A. Gurwell, Nicole M. Ford, Kazuhiro Hada, Sera Markoff, Mark R. Morris, Joey Neilsen, Nadeen B. Sabha and Braden Seefeldt-Gail
The time-variable emission from the accretion flow of Sgr A*, the supermassive black hole at the Galactic center, has long been examined in the radio-to-millimeter, near-infrared (NIR), and X-ray regimes of the electromagnetic spectrum. However, until now, sensitivity and angular resolution have been insufficient in the crucial mid-infrared (MIR) regime. The MIRI instrument on JWST has changed that, and we report the first MIR detection of Sgr A*. The detection was during a flare that lasted about 40 minutes, a duration similar to NIR and X-ray flares, and the source's spectral index steepened as the flare ended. The steepening suggests that synchrotron cooling is an important process for Sgr A*'s variability and implies magnetic fields strengths ~ 40–70 G in the emission zone. Observations at 1.3 mm with the Submillimeter Array revealed a counterpart flare lagging the MIR flare by ≈10 minutes. The observations can be self-consistently explained as synchrotron radiation from a single population of gradually cooling high-energy electrons accelerated through (a combination of) magnetic reconnection and/or magnetized turbulence.
{"title":"First Mid-infrared Detection and Modeling of a Flare from Sgr A*","authors":"Sebastiano D. von Fellenberg, Tamojeet Roychowdhury, Joseph M. Michail, Zach Sumners, Grace Sanger-Johnson, Giovanni G. Fazio, Daryl Haggard, Joseph L. Hora, Alexander Philippov, Bart Ripperda, Howard A. Smith, S. P. Willner, Gunther Witzel, Shuo Zhang, Eric E. Becklin, Geoffrey C. Bower, Sunil Chandra, Tuan Do, Macarena Garcia Marin, Mark A. Gurwell, Nicole M. Ford, Kazuhiro Hada, Sera Markoff, Mark R. Morris, Joey Neilsen, Nadeen B. Sabha and Braden Seefeldt-Gail","doi":"10.3847/2041-8213/ada3d2","DOIUrl":"https://doi.org/10.3847/2041-8213/ada3d2","url":null,"abstract":"The time-variable emission from the accretion flow of Sgr A*, the supermassive black hole at the Galactic center, has long been examined in the radio-to-millimeter, near-infrared (NIR), and X-ray regimes of the electromagnetic spectrum. However, until now, sensitivity and angular resolution have been insufficient in the crucial mid-infrared (MIR) regime. The MIRI instrument on JWST has changed that, and we report the first MIR detection of Sgr A*. The detection was during a flare that lasted about 40 minutes, a duration similar to NIR and X-ray flares, and the source's spectral index steepened as the flare ended. The steepening suggests that synchrotron cooling is an important process for Sgr A*'s variability and implies magnetic fields strengths ~ 40–70 G in the emission zone. Observations at 1.3 mm with the Submillimeter Array revealed a counterpart flare lagging the MIR flare by ≈10 minutes. The observations can be self-consistently explained as synchrotron radiation from a single population of gradually cooling high-energy electrons accelerated through (a combination of) magnetic reconnection and/or magnetized turbulence.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142991447","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}