Pub Date : 2025-01-16DOI: 10.3847/1538-4357/ad96ac
Mona Shishido, Yuusuke Uchida and Takayoshi Kohmura
We present a systematic study of the thermodynamic properties of the intracluster medium (ICM), including the plasma conditions in the ICM, in the merging galaxy cluster A3667 using Suzaku. We analyze the X-ray spectra of the ICM between the northwestern and the southeastern radio relics across a prominent cold front in A3667 to search for the ICM in a nonequilibrium ionization (NEI) state. We find that the ICM inside the cold front exhibits an NEI state with an ionization parameter of (2.2 ± 0.4) × 1011 s cm−3 at the 90% confidence level, which is lower than that expected from a collisional ionization equilibrium state of the ICM (i.e., net > 1012 s cm−3). The timescale calculated from the ionization parameter of the ICM inside the cold front is , which is much shorter than the thermal equilibration timescale. A weak transonic sloshing motion might explain the possibility that the ICM inside the cold front of A3667 is in the NEI state. In addition, the NEI state of the ICM in A3667 seems to be associated with the elongated radio halo bridging the region between the northwestern radio relic and the prominent cold front in A3667 across the cluster center.
{"title":"Suzaku Observations of the Cold Front in A3667: A Nonequilibrium Ionization State of the Intracluster Medium","authors":"Mona Shishido, Yuusuke Uchida and Takayoshi Kohmura","doi":"10.3847/1538-4357/ad96ac","DOIUrl":"https://doi.org/10.3847/1538-4357/ad96ac","url":null,"abstract":"We present a systematic study of the thermodynamic properties of the intracluster medium (ICM), including the plasma conditions in the ICM, in the merging galaxy cluster A3667 using Suzaku. We analyze the X-ray spectra of the ICM between the northwestern and the southeastern radio relics across a prominent cold front in A3667 to search for the ICM in a nonequilibrium ionization (NEI) state. We find that the ICM inside the cold front exhibits an NEI state with an ionization parameter of (2.2 ± 0.4) × 1011 s cm−3 at the 90% confidence level, which is lower than that expected from a collisional ionization equilibrium state of the ICM (i.e., net > 1012 s cm−3). The timescale calculated from the ionization parameter of the ICM inside the cold front is , which is much shorter than the thermal equilibration timescale. A weak transonic sloshing motion might explain the possibility that the ICM inside the cold front of A3667 is in the NEI state. In addition, the NEI state of the ICM in A3667 seems to be associated with the elongated radio halo bridging the region between the northwestern radio relic and the prominent cold front in A3667 across the cluster center.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986093","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 : 2025-01-16DOI: 10.3847/1538-4357/ad991f
Dingyi Zhao, Yingjie Peng, Yipeng Jing, Xiaohu Yang, Luis C. Ho, Alvio Renzini, Anna R. Gallazzi, Cheqiu Lyu, Roberto Maiolino, Jing Dou, Zeyu Gao, Qiusheng Gu, Filippo Mannucci, Houjun Mo, Bitao Wang, Enci Wang, Kai Wang, Yu-Chen Wang, Bingxiao Xu, Feng Yuan and Xingye Zhu
In ΛCDM cosmology, galaxies form and evolve in their host dark matter (DM) halos. Halo mass is crucial for understanding the halo–galaxy connection. The abundance-matching (AM) technique has been widely used to derive the halo masses of galaxy groups. However, the quenching of the central galaxy can decouple the coevolution of its stellar mass and DM halo mass. Different halo assembly histories can also result in significantly different final stellar masses of the central galaxies. These processes can introduce substantial uncertainties into the halo masses derived from the AM method, particularly leading to a systematic bias between groups with star-forming centrals (blue groups) and passive centrals (red groups). To improve this, we have developed a new machine learning (ML) algorithm that accounts for these effects and is trained on simulations. Our results show that the ML method eliminates the systematic bias in the derived halo masses for blue and red groups and is, on average, ~one-third more accurate than the AM method. With careful calibrations of observable quantities from simulations and observations from the Sloan Digital Sky Survey (SDSS), we apply our ML model to the SDSS groups to derive their halo masses down to 1011.5M⊙ or even lower. The derived SDSS group halo mass function agrees well with the theoretical predictions, and the derived stellar-to-halo mass relations for both the red and blue groups match well with those obtained from direct weak-lensing measurements. These new halo mass estimates enable more accurate investigation of the galaxy–halo connection and the role of halos in galaxy evolution.
{"title":"From Halos to Galaxies. VI. Improved Halo Mass Estimation for SDSS Groups and Measurement of the Halo Mass Function","authors":"Dingyi Zhao, Yingjie Peng, Yipeng Jing, Xiaohu Yang, Luis C. Ho, Alvio Renzini, Anna R. Gallazzi, Cheqiu Lyu, Roberto Maiolino, Jing Dou, Zeyu Gao, Qiusheng Gu, Filippo Mannucci, Houjun Mo, Bitao Wang, Enci Wang, Kai Wang, Yu-Chen Wang, Bingxiao Xu, Feng Yuan and Xingye Zhu","doi":"10.3847/1538-4357/ad991f","DOIUrl":"https://doi.org/10.3847/1538-4357/ad991f","url":null,"abstract":"In ΛCDM cosmology, galaxies form and evolve in their host dark matter (DM) halos. Halo mass is crucial for understanding the halo–galaxy connection. The abundance-matching (AM) technique has been widely used to derive the halo masses of galaxy groups. However, the quenching of the central galaxy can decouple the coevolution of its stellar mass and DM halo mass. Different halo assembly histories can also result in significantly different final stellar masses of the central galaxies. These processes can introduce substantial uncertainties into the halo masses derived from the AM method, particularly leading to a systematic bias between groups with star-forming centrals (blue groups) and passive centrals (red groups). To improve this, we have developed a new machine learning (ML) algorithm that accounts for these effects and is trained on simulations. Our results show that the ML method eliminates the systematic bias in the derived halo masses for blue and red groups and is, on average, ~one-third more accurate than the AM method. With careful calibrations of observable quantities from simulations and observations from the Sloan Digital Sky Survey (SDSS), we apply our ML model to the SDSS groups to derive their halo masses down to 1011.5M⊙ or even lower. The derived SDSS group halo mass function agrees well with the theoretical predictions, and the derived stellar-to-halo mass relations for both the red and blue groups match well with those obtained from direct weak-lensing measurements. These new halo mass estimates enable more accurate investigation of the galaxy–halo connection and the role of halos in galaxy evolution.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"18 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986098","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 : 2025-01-16DOI: 10.3847/1538-4357/ad9aa4
Devontae C. Baxter, Sean P. Fillingham, Alison L. Coil and Michael C. Cooper
We present results from a Keck/DEIMOS survey to study satellite quenching in group environments at z ~ 0.8 within the Extended Groth Strip (EGS). We target 11 groups in the EGS with extended X-ray emission. We obtain high-quality spectroscopic redshifts for group member candidates, extending to depths over 1 order of magnitude fainter than existing DEEP2/DEEP3 spectroscopy. This depth enables the first spectroscopic measurement of the satellite quiescent fraction down to stellar masses of ~109.5M⊙ at this redshift. By combining an infall-based environmental quenching model, constrained by the observed quiescent fractions, with infall histories of simulated groups from the IllustrisTNG100-1-Dark simulation, we estimate environmental quenching timescales (τquench) for the observed group population. At high stellar masses (M⋆ = 1010.5M⊙) we find that Gyr, which is consistent with previous estimates at this epoch. At lower stellar masses (M⋆ = 109.5M⊙), we find that Gyr, which is shorter than prior estimates from photometry-based investigations. These timescales are consistent with satellite quenching via starvation, provided the hot gas envelope of infalling satellites is not stripped away. We find that the evolution in the quenching timescale between 0
{"title":"The Importance of Gas Starvation in Driving Satellite Quenching in Galaxy Groups at z ~ 0.8","authors":"Devontae C. Baxter, Sean P. Fillingham, Alison L. Coil and Michael C. Cooper","doi":"10.3847/1538-4357/ad9aa4","DOIUrl":"https://doi.org/10.3847/1538-4357/ad9aa4","url":null,"abstract":"We present results from a Keck/DEIMOS survey to study satellite quenching in group environments at z ~ 0.8 within the Extended Groth Strip (EGS). We target 11 groups in the EGS with extended X-ray emission. We obtain high-quality spectroscopic redshifts for group member candidates, extending to depths over 1 order of magnitude fainter than existing DEEP2/DEEP3 spectroscopy. This depth enables the first spectroscopic measurement of the satellite quiescent fraction down to stellar masses of ~109.5M⊙ at this redshift. By combining an infall-based environmental quenching model, constrained by the observed quiescent fractions, with infall histories of simulated groups from the IllustrisTNG100-1-Dark simulation, we estimate environmental quenching timescales (τquench) for the observed group population. At high stellar masses (M⋆ = 1010.5M⊙) we find that Gyr, which is consistent with previous estimates at this epoch. At lower stellar masses (M⋆ = 109.5M⊙), we find that Gyr, which is shorter than prior estimates from photometry-based investigations. These timescales are consistent with satellite quenching via starvation, provided the hot gas envelope of infalling satellites is not stripped away. We find that the evolution in the quenching timescale between 0 <z <1 aligns with the evolution in the dynamical time of the host halo and the total cold gas depletion time. This suggests that the doubling of the quenching timescale in groups since z ~ 1 could be related to the dynamical evolution of groups or a decrease in quenching efficiency via starvation with decreasing redshift.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"53 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986099","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 : 2025-01-16DOI: 10.3847/1538-4357/ad9ea1
Yehao Cheng, Yu Pan, Yuan-Pei Yang, Jinghua Zhang, Guowang Du, Yuan Fang, Brajesh Kumar, Helong Guo, Xinzhong Er, Xinlei Chen, Chenxu Liu, Tao Wang, Zhenfei Qin, Yicheng Jin, Xingzhu Zou, Xuhui Han, Pinpin Zhang, Liping Xin, Chao Wu, Jianhui Lian, Xiangkun Liu and Xiaowei Liu
Gamma-ray bursts (GRBs) are the most luminous transients in the Universe. The interaction of the relativistic jet with the circumburst medium produces an afterglow and generates multiwavelength emission. In this work, we present simultaneous multiband photometry of GRB 240825A with the Multi-channel Photometric Survey Telescope (Mephisto) and analyze its temporal and spectral properties. The measurement began 128 s after the GRB trigger and continued until the fourth day, when the afterglow essentially diminished and the measured brightness was close to that of the host galaxy. Based on the multiband light curves in the uvgriz bands, we find that the optical flux density satisfies Fν,obs ∝ t−1.34ν−2.48 with a spectral index of 2.48, much larger than those of most other GRBs. To reconcile the measured much softer spectral energy distribution (SED) with that predicted by the standard afterglow model, an extra host-galaxy extinction of EB−V ∼ (0.37–0.57) mag is required. We interpreted this excess as arising from a dense circumburst medium. We further find that the SED of the optical afterglow hardened as the afterglow decayed and the color excess EB−V decreased ∼0.26 mag from 100 to 3000 s after the GRB trigger. Finally, we analyze the properties of the host galaxy of GRB 240825A based on data from the Sloan Digital Sky Survey, the Pan-STARRS survey, and the HSC-SSP survey. For a host redshift of z = 0.659, the stellar mass and star formation rate of the host galaxy are estimated to be and , respectively, pointing to a gas-rich, star-forming, medium-size galaxy.
{"title":"Simultaneous Multiband Photometry of the Early Optical Afterglow of GRB 240825A with Mephisto","authors":"Yehao Cheng, Yu Pan, Yuan-Pei Yang, Jinghua Zhang, Guowang Du, Yuan Fang, Brajesh Kumar, Helong Guo, Xinzhong Er, Xinlei Chen, Chenxu Liu, Tao Wang, Zhenfei Qin, Yicheng Jin, Xingzhu Zou, Xuhui Han, Pinpin Zhang, Liping Xin, Chao Wu, Jianhui Lian, Xiangkun Liu and Xiaowei Liu","doi":"10.3847/1538-4357/ad9ea1","DOIUrl":"https://doi.org/10.3847/1538-4357/ad9ea1","url":null,"abstract":"Gamma-ray bursts (GRBs) are the most luminous transients in the Universe. The interaction of the relativistic jet with the circumburst medium produces an afterglow and generates multiwavelength emission. In this work, we present simultaneous multiband photometry of GRB 240825A with the Multi-channel Photometric Survey Telescope (Mephisto) and analyze its temporal and spectral properties. The measurement began 128 s after the GRB trigger and continued until the fourth day, when the afterglow essentially diminished and the measured brightness was close to that of the host galaxy. Based on the multiband light curves in the uvgriz bands, we find that the optical flux density satisfies Fν,obs ∝ t−1.34ν−2.48 with a spectral index of 2.48, much larger than those of most other GRBs. To reconcile the measured much softer spectral energy distribution (SED) with that predicted by the standard afterglow model, an extra host-galaxy extinction of EB−V ∼ (0.37–0.57) mag is required. We interpreted this excess as arising from a dense circumburst medium. We further find that the SED of the optical afterglow hardened as the afterglow decayed and the color excess EB−V decreased ∼0.26 mag from 100 to 3000 s after the GRB trigger. Finally, we analyze the properties of the host galaxy of GRB 240825A based on data from the Sloan Digital Sky Survey, the Pan-STARRS survey, and the HSC-SSP survey. For a host redshift of z = 0.659, the stellar mass and star formation rate of the host galaxy are estimated to be and , respectively, pointing to a gas-rich, star-forming, medium-size galaxy.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"74 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986102","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 : 2025-01-16DOI: 10.3847/1538-4357/ad98ea
Ulrich P. Steinwandel and Jared A. Goldberg
We present results from galaxy evolution simulations with a multiphase interstellar medium (ISM), a mass resolution of 4 M⊙, and a spatial resolution of 0.5 pc. These simulations include a resolved stellar stellar feedback model. Our fiducial run WLM-fid adopts 1051 erg for the supernova (SN) energy. Among the remaining seven simulations, there are two runs where we vary this number by fixing the energy at 1050 erg and 1052 erg (WLM-1e50 and WLM-1e52). Additionally, we carry out one run with variable SN-energy (WLM-variable) and run two simulations where only 10% or 60% of stars explode as SNe with 1051 erg, while the remaining stars do not explode (WLM-60prob and WLM-10prob). We find that the variation in the SN energy, has only minor effects: the star formation rate changes by roughly a factor of 2 compared to WLM-fid, and the strength of the galactic outflows in mass and energy is reduced by 30%, with typical values of ηm ∼ 0.1 and ηe ∼ 0.05 (at a height of 3 kpc after the hot wind is fully decoupled from the galactic ISM). In contrast, the increase and decrease in the canonical SN-energy have a clear impact on the phase structure, with loading factors that are at least 10 times lower/higher and a clear change in the phase structure (the energy loading is normalized self-consistently to the initial mass function averaged explosion energy). We conclude that these modulations are driven not by the minor change in SN-energy but rather by the likelihood of whether or not an event occurs when variable SN energies are applied.
{"title":"Some Stars Fade Quietly: Varied Supernova Explosion Outcomes and Their Effects on the Multiphase Interstellar Medium","authors":"Ulrich P. Steinwandel and Jared A. Goldberg","doi":"10.3847/1538-4357/ad98ea","DOIUrl":"https://doi.org/10.3847/1538-4357/ad98ea","url":null,"abstract":"We present results from galaxy evolution simulations with a multiphase interstellar medium (ISM), a mass resolution of 4 M⊙, and a spatial resolution of 0.5 pc. These simulations include a resolved stellar stellar feedback model. Our fiducial run WLM-fid adopts 1051 erg for the supernova (SN) energy. Among the remaining seven simulations, there are two runs where we vary this number by fixing the energy at 1050 erg and 1052 erg (WLM-1e50 and WLM-1e52). Additionally, we carry out one run with variable SN-energy (WLM-variable) and run two simulations where only 10% or 60% of stars explode as SNe with 1051 erg, while the remaining stars do not explode (WLM-60prob and WLM-10prob). We find that the variation in the SN energy, has only minor effects: the star formation rate changes by roughly a factor of 2 compared to WLM-fid, and the strength of the galactic outflows in mass and energy is reduced by 30%, with typical values of ηm ∼ 0.1 and ηe ∼ 0.05 (at a height of 3 kpc after the hot wind is fully decoupled from the galactic ISM). In contrast, the increase and decrease in the canonical SN-energy have a clear impact on the phase structure, with loading factors that are at least 10 times lower/higher and a clear change in the phase structure (the energy loading is normalized self-consistently to the initial mass function averaged explosion energy). We conclude that these modulations are driven not by the minor change in SN-energy but rather by the likelihood of whether or not an event occurs when variable SN energies are applied.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986096","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 : 2025-01-16DOI: 10.3847/1538-4357/ad9335
Hisashi Hayakawa, Yusuke Ebihara, Alexander Mishev, Sergey Koldobskiy, Kanya Kusano, Sabrina Bechet, Seiji Yashiro, Kazumasa Iwai, Atsuki Shinbori, Kalevi Mursula, Fusa Miyake, Daikou Shiota, Marcos V. D. Silveira, Robert Stuart, Denny M. Oliveira, Sachiko Akiyama, Kouji Ohnishi, Vincent Ledvina and Yoshizumi Miyoshi
In 2024 May, the scientific community observed intense solar eruptions that resulted in a great geomagnetic storm and auroral extensions, highlighting the need to document and quantify these events. This study mainly focuses on their quantification. The source active region (AR; NOAA Active Region 13664) evolved from 113 to 2761 millionths of the solar hemisphere between May 4 and 14. NOAA AR 13664’s magnetic free energy surpassed 1033 erg on May 7, triggering 12 X-class flares on May 8–15. Multiple interplanetary coronal mass ejections (ICMEs) were produced from this AR, accelerating solar energetic particles toward Earth. According to satellite and interplanetary scintillation data, at least four ICMEs erupted from AR 13664, eventually overcoming and combining each other. The shock arrival at 17:05 UT on May 10 significantly compressed the magnetosphere down to ≈5.04 RE and triggered a deep Forbush Decrease. GOES satellite data and ground-based neutron monitors confirmed a ground-level enhancement from 2 UT to 10 UT on 2024 May 11. The ICMEs induced exceptional geomagnetic storms, peaking at a provisional Dst index of −412 nT at 2 UT on May 11, marking the sixth-largest storm since 1957. The AE and AL indices showed great auroral extensions that located the AE/AL stations into the polar cap. We gathered auroral records at that time and reconstructed the equatorward boundary of the visual auroral oval to 29.°8 invariant latitude. We compared naked-eye and camera auroral visibility, providing critical caveats on their difference. We also confirmed global disturbances of the storm-enhanced density of the ionosphere.
{"title":"The Solar and Geomagnetic Storms in 2024 May: A Flash Data Report","authors":"Hisashi Hayakawa, Yusuke Ebihara, Alexander Mishev, Sergey Koldobskiy, Kanya Kusano, Sabrina Bechet, Seiji Yashiro, Kazumasa Iwai, Atsuki Shinbori, Kalevi Mursula, Fusa Miyake, Daikou Shiota, Marcos V. D. Silveira, Robert Stuart, Denny M. Oliveira, Sachiko Akiyama, Kouji Ohnishi, Vincent Ledvina and Yoshizumi Miyoshi","doi":"10.3847/1538-4357/ad9335","DOIUrl":"https://doi.org/10.3847/1538-4357/ad9335","url":null,"abstract":"In 2024 May, the scientific community observed intense solar eruptions that resulted in a great geomagnetic storm and auroral extensions, highlighting the need to document and quantify these events. This study mainly focuses on their quantification. The source active region (AR; NOAA Active Region 13664) evolved from 113 to 2761 millionths of the solar hemisphere between May 4 and 14. NOAA AR 13664’s magnetic free energy surpassed 1033 erg on May 7, triggering 12 X-class flares on May 8–15. Multiple interplanetary coronal mass ejections (ICMEs) were produced from this AR, accelerating solar energetic particles toward Earth. According to satellite and interplanetary scintillation data, at least four ICMEs erupted from AR 13664, eventually overcoming and combining each other. The shock arrival at 17:05 UT on May 10 significantly compressed the magnetosphere down to ≈5.04 RE and triggered a deep Forbush Decrease. GOES satellite data and ground-based neutron monitors confirmed a ground-level enhancement from 2 UT to 10 UT on 2024 May 11. The ICMEs induced exceptional geomagnetic storms, peaking at a provisional Dst index of −412 nT at 2 UT on May 11, marking the sixth-largest storm since 1957. The AE and AL indices showed great auroral extensions that located the AE/AL stations into the polar cap. We gathered auroral records at that time and reconstructed the equatorward boundary of the visual auroral oval to 29.°8 invariant latitude. We compared naked-eye and camera auroral visibility, providing critical caveats on their difference. We also confirmed global disturbances of the storm-enhanced density of the ionosphere.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"11 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142988492","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 : 2025-01-16DOI: 10.3847/1538-4357/ad9746
Ayano Komaki and Naoki Yoshida
We study the effect of stellar evolution on the dispersal of protoplanetary disks by performing one-dimensional simulations of long-term disk evolution. Our simulations include viscous disk accretion, magnetohydrodynamic winds, and photoevaporation as important disk dispersal processes. We consider a wide range of stellar mass of 0.1–7 M⊙ and incorporate the luminosity evolution of the central star. For solar-mass stars, stellar evolution delays the disk dispersal time as the far-ultraviolet (FUV) luminosity decreases toward the main sequence. In the case of intermediate-mass stars, the FUV luminosity increases significantly over a few million years, driving strong photoevaporation and enhancing disk mass loss during the later stages of disk evolution. This highlights the limitations of assuming a constant FUV luminosity throughout a simulation. Photoevaporation primarily impacts the outer regions of the disk and is the dominant disk dispersal process in the late evolutionary stage. Based on the results of a large set of simulations, we study the evolution of a population of star–disk systems and derive the disk fraction as a function of time. We demonstrate that the inclusion of stellar luminosity evolution can alter the disk fraction by several tens of percent, bringing the simulations into closer agreement with recent observations. We argue that it is important to include the stellar luminosity evolution in simulations of the long-term dispersal of protoplanetary disks.
{"title":"The Effect of Stellar Evolution on Dispersal of Protoplanetary Disks: Disk Fraction in Star-forming Regions","authors":"Ayano Komaki and Naoki Yoshida","doi":"10.3847/1538-4357/ad9746","DOIUrl":"https://doi.org/10.3847/1538-4357/ad9746","url":null,"abstract":"We study the effect of stellar evolution on the dispersal of protoplanetary disks by performing one-dimensional simulations of long-term disk evolution. Our simulations include viscous disk accretion, magnetohydrodynamic winds, and photoevaporation as important disk dispersal processes. We consider a wide range of stellar mass of 0.1–7 M⊙ and incorporate the luminosity evolution of the central star. For solar-mass stars, stellar evolution delays the disk dispersal time as the far-ultraviolet (FUV) luminosity decreases toward the main sequence. In the case of intermediate-mass stars, the FUV luminosity increases significantly over a few million years, driving strong photoevaporation and enhancing disk mass loss during the later stages of disk evolution. This highlights the limitations of assuming a constant FUV luminosity throughout a simulation. Photoevaporation primarily impacts the outer regions of the disk and is the dominant disk dispersal process in the late evolutionary stage. Based on the results of a large set of simulations, we study the evolution of a population of star–disk systems and derive the disk fraction as a function of time. We demonstrate that the inclusion of stellar luminosity evolution can alter the disk fraction by several tens of percent, bringing the simulations into closer agreement with recent observations. We argue that it is important to include the stellar luminosity evolution in simulations of the long-term dispersal of protoplanetary disks.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986094","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 : 2025-01-16DOI: 10.3847/1538-4357/ad9449
Dotan Gazith, Aaron B. Pearlman and Barak Zackay
The strict periodicity of pulsars is one of the primary ways through which their nature and environment can be studied, and it has also enabled precision tests of general relativity and studies of nanohertz gravitational waves using pulsar timing arrays (PTAs). Identifying such a periodicity from a discrete set of arrival times is a difficult algorithmic problem, In particular when the pulsar is in a binary system. This challenge is especially acute in γ-ray pulsar astronomy, as there are hundreds of unassociated Fermi-LAT sources that may be produced by γ-ray emission from unknown pulsars. Recovering their timing solutions will help reveal their properties and may allow them to be added to PTAs. The same issue arises when attempting to recover a strict periodicity for repeating fast radio bursts (FRBs). Such a detection would be a major breakthrough, providing us with the FRB source’s age, magnetic field, and binary orbit. The problem of recovering a timing solution from sparse time-of-arrival data is currently unsolvable for pulsars in unknown binary systems, and incredibly hard even for isolated pulsars. In this paper, we frame the timing recovery problem as the problem of finding a short vector in a lattice and obtain the solution using off-the-shelf lattice reduction and sieving techniques. As a proof of concept, we solve PSR J0318+0253, a millisecond γ-ray pulsar discovered by FAST in a γ-ray-directed search, in a few CPU minutes. We discuss the assumptions of the standard lattice techniques and quantify their performance and limitations.
{"title":"Recovering Pulsar Periodicity from Time-of-arrival Data by Finding the Shortest Vector in a Lattice","authors":"Dotan Gazith, Aaron B. Pearlman and Barak Zackay","doi":"10.3847/1538-4357/ad9449","DOIUrl":"https://doi.org/10.3847/1538-4357/ad9449","url":null,"abstract":"The strict periodicity of pulsars is one of the primary ways through which their nature and environment can be studied, and it has also enabled precision tests of general relativity and studies of nanohertz gravitational waves using pulsar timing arrays (PTAs). Identifying such a periodicity from a discrete set of arrival times is a difficult algorithmic problem, In particular when the pulsar is in a binary system. This challenge is especially acute in γ-ray pulsar astronomy, as there are hundreds of unassociated Fermi-LAT sources that may be produced by γ-ray emission from unknown pulsars. Recovering their timing solutions will help reveal their properties and may allow them to be added to PTAs. The same issue arises when attempting to recover a strict periodicity for repeating fast radio bursts (FRBs). Such a detection would be a major breakthrough, providing us with the FRB source’s age, magnetic field, and binary orbit. The problem of recovering a timing solution from sparse time-of-arrival data is currently unsolvable for pulsars in unknown binary systems, and incredibly hard even for isolated pulsars. In this paper, we frame the timing recovery problem as the problem of finding a short vector in a lattice and obtain the solution using off-the-shelf lattice reduction and sieving techniques. As a proof of concept, we solve PSR J0318+0253, a millisecond γ-ray pulsar discovered by FAST in a γ-ray-directed search, in a few CPU minutes. We discuss the assumptions of the standard lattice techniques and quantify their performance and limitations.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986092","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 : 2025-01-16DOI: 10.3847/1538-4357/ad9827
Aomawa L. Shields, Eric T. Wolf, Eric Agol and Pier-Emmanuel Tremblay
Discoveries of giant planet candidates orbiting white dwarf (WD) stars and the demonstrated capabilities of the James Webb Space Telescope bring the possibility of detecting rocky planets in the habitable zones (HZs) of WDs into pertinent focus. We present simulations of an aqua planet with an Earth-like atmospheric composition and incident stellar insolation orbiting in the HZ of two different types of stars—a 5000 K WD and main-sequence K-dwarf star Kepler-62 (K62) with a similar effective temperature—and identify the mechanisms responsible for the two differing planetary climates. The synchronously rotating WD planet's global mean surface temperature is 25 K higher than that of the synchronously rotating planet orbiting K62, due to its much faster (10 hr) rotation and orbital period. This ultrafast rotation generates strong zonal winds and meridional flux of zonal momentum, stretching out and homogenizing the scale of atmospheric circulation, and preventing an equivalent buildup of thick, liquid water clouds on the dayside of the planet compared to the synchronous planet orbiting K62, while also transporting heat equatorward from higher latitudes. White dwarfs may therefore present amenable environments for life on planets formed within or migrated to their HZs, generating warmer surface environments than those of planets with main-sequence hosts to compensate for an ever shrinking incident stellar flux.
{"title":"Increased Surface Temperatures of Habitable White Dwarf Worlds Relative to Main-sequence Exoplanets","authors":"Aomawa L. Shields, Eric T. Wolf, Eric Agol and Pier-Emmanuel Tremblay","doi":"10.3847/1538-4357/ad9827","DOIUrl":"https://doi.org/10.3847/1538-4357/ad9827","url":null,"abstract":"Discoveries of giant planet candidates orbiting white dwarf (WD) stars and the demonstrated capabilities of the James Webb Space Telescope bring the possibility of detecting rocky planets in the habitable zones (HZs) of WDs into pertinent focus. We present simulations of an aqua planet with an Earth-like atmospheric composition and incident stellar insolation orbiting in the HZ of two different types of stars—a 5000 K WD and main-sequence K-dwarf star Kepler-62 (K62) with a similar effective temperature—and identify the mechanisms responsible for the two differing planetary climates. The synchronously rotating WD planet's global mean surface temperature is 25 K higher than that of the synchronously rotating planet orbiting K62, due to its much faster (10 hr) rotation and orbital period. This ultrafast rotation generates strong zonal winds and meridional flux of zonal momentum, stretching out and homogenizing the scale of atmospheric circulation, and preventing an equivalent buildup of thick, liquid water clouds on the dayside of the planet compared to the synchronous planet orbiting K62, while also transporting heat equatorward from higher latitudes. White dwarfs may therefore present amenable environments for life on planets formed within or migrated to their HZs, generating warmer surface environments than those of planets with main-sequence hosts to compensate for an ever shrinking incident stellar flux.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986095","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 : 2025-01-16DOI: 10.3847/1538-4357/ad9f35
Ellen M. Price, Eric Van Clepper and Fred J. Ciesla
Hydrodynamical simulations of protoplanetary disk dynamics are useful tools for understanding the formation of planetary systems, including our own. Approximations are necessary to make these simulations computationally tractable. A common assumption when simulating dust fluids is that of a constant Stokes number, a dimensionless number that characterizes the interaction between a particle and the surrounding gas. Constant Stokes number is not a good approximation in regions of the disk where the gas density changes significantly, such as near a planet-induced gap. In this paper, we relax the assumption of a constant Stokes number in the popular FARGO3D code using semianalytic equations for the drag force on dust particles, which enables an assumption of constant particle size instead. We explore the effect this change has on disk morphology and particle fluxes across the gap for both outward- and inward-drifting particles. The assumption of constant particle size, rather than constant Stokes number, is shown to make a significant difference in some cases, emphasizing the importance of the more accurate treatment.
{"title":"Dynamics of Small, Constant-size Particles in a Protoplanetary Disk with an Embedded Protoplanet","authors":"Ellen M. Price, Eric Van Clepper and Fred J. Ciesla","doi":"10.3847/1538-4357/ad9f35","DOIUrl":"https://doi.org/10.3847/1538-4357/ad9f35","url":null,"abstract":"Hydrodynamical simulations of protoplanetary disk dynamics are useful tools for understanding the formation of planetary systems, including our own. Approximations are necessary to make these simulations computationally tractable. A common assumption when simulating dust fluids is that of a constant Stokes number, a dimensionless number that characterizes the interaction between a particle and the surrounding gas. Constant Stokes number is not a good approximation in regions of the disk where the gas density changes significantly, such as near a planet-induced gap. In this paper, we relax the assumption of a constant Stokes number in the popular FARGO3D code using semianalytic equations for the drag force on dust particles, which enables an assumption of constant particle size instead. We explore the effect this change has on disk morphology and particle fluxes across the gap for both outward- and inward-drifting particles. The assumption of constant particle size, rather than constant Stokes number, is shown to make a significant difference in some cases, emphasizing the importance of the more accurate treatment.","PeriodicalId":501813,"journal":{"name":"The Astrophysical Journal","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142986103","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}
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