Pub Date : 2026-02-17DOI: 10.3847/2041-8213/ae40bf
Helena García Escudero, Seyed Hamidreza Mirpoorian and Levon Pogosian
We present a sound-horizon-agnostic determination of the Hubble constant, H0, by combining DESI Data Release 2 baryon acoustic oscillations (BAO) data with the latest cosmic microwave background (CMB) lensing measurements from Planck, the Atacama Cosmology Telescope, and SPT-3G, the angular size of the CMB acoustic scale, Dark Energy Survey Year 3 (3 × 2 pt) galaxy weak lensing and clustering correlations, and the Pantheon+ supernova sample. In this analysis, The sound horizon at the drag epoch, rd, is treated as a free parameter. By combining uncalibrated comoving distances from BAO and supernovae with constraints on the matter density Ωmh2 from CMB and galaxy lensing and clustering, we break the rd–H0 degeneracy and obtain H0 = 70.0 ± 1.7 km s−1 Mpc−1 when the sum of the neutrino masses is fixed at Σmν = 0.06 eV. With an informative prior on the amplitude of primordial fluctuations, As, we find H0 = 70.03 ± 0.9 km s−1 Mpc−1. Allowing Σmν to vary, we find that the neutrino mass is weakly constrained and strongly prior dependent. Consequently, the inferred H0 is sensitive to the choice of the Σmν prior, with a uniform prior biasing results toward larger neutrino masses and higher H0, while a logarithmic prior reduces this bias significantly. Forecasts for the completed DESI BAO program, combined with Simons Observatory–like CMB lensing, next-generation 3 × 2 pt data, and expanded supernova samples predict σ(H0) ≃ 0.67 km s−1 Mpc−1 with fixed Σmν, and σ(H0) ≃ 1.1 km s−1 Mpc−1 with Σmν < 0.133 eV (<0.263 eV) at 68% (95%) confidence limit when Σmν is varied.
我们将DESI Data Release 2重子声学振荡（BAO）数据与普朗克、阿塔卡马宇宙学望远镜和SPT-3G的最新宇宙微波背景（CMB）透镜测量数据、CMB声学尺度的角大小、暗能量调查第3年（3 × 2 pt）星系弱透镜和聚类相关性以及万神殿+超新星样本相结合，提出了哈勃常数H0的声视界不可知测定。在这个分析中，声视界在拖拽时期，rd，被视为一个自由参数。结合未校准的BAO和超新星的共移动距离，以及来自CMB的物质密度Ωmh2和星系透镜和聚集的约束，我们打破了rd-H0简并，得到当中微子质量之和固定为Σmν = 0.06 eV时，H0 = 70.0±1.7 km s−1 Mpc−1。通过对原始波动幅度As的先验信息，我们发现H0 = 70.03±0.9 km s−1 Mpc−1。允许Σmν变化，我们发现中微子质量是弱约束和强先验依赖的。因此，推断的H0对Σmν先验的选择很敏感，具有均匀的先验偏倚结果，倾向于更大的中微子质量和更高的H0，而对数先验显着降低了这种偏差。结合Simons天文台类CMB透镜、新一代3 × 2 pt数据和扩展的超新星样本，对DESI BAO项目完成的预测表明，当Σmν变化时，σ(H0)≃0.67 km s−1 Mpc−1的置信限为68%(95%)，当Σmν < 0.133 eV （<0.263 eV）时σ(H0)的置信限为Σmν。
{"title":"Sound-horizon-agnostic Inference of the Hubble Constant and Neutrino Masses from Baryon Acoustic Oscillations, Cosmic Microwave Background Lensing, and Galaxy Weak Lensing and Clustering","authors":"Helena García Escudero, Seyed Hamidreza Mirpoorian and Levon Pogosian","doi":"10.3847/2041-8213/ae40bf","DOIUrl":"https://doi.org/10.3847/2041-8213/ae40bf","url":null,"abstract":"We present a sound-horizon-agnostic determination of the Hubble constant, H0, by combining DESI Data Release 2 baryon acoustic oscillations (BAO) data with the latest cosmic microwave background (CMB) lensing measurements from Planck, the Atacama Cosmology Telescope, and SPT-3G, the angular size of the CMB acoustic scale, Dark Energy Survey Year 3 (3 × 2 pt) galaxy weak lensing and clustering correlations, and the Pantheon+ supernova sample. In this analysis, The sound horizon at the drag epoch, rd, is treated as a free parameter. By combining uncalibrated comoving distances from BAO and supernovae with constraints on the matter density Ωmh2 from CMB and galaxy lensing and clustering, we break the rd–H0 degeneracy and obtain H0 = 70.0 ± 1.7 km s−1 Mpc−1 when the sum of the neutrino masses is fixed at Σmν = 0.06 eV. With an informative prior on the amplitude of primordial fluctuations, As, we find H0 = 70.03 ± 0.9 km s−1 Mpc−1. Allowing Σmν to vary, we find that the neutrino mass is weakly constrained and strongly prior dependent. Consequently, the inferred H0 is sensitive to the choice of the Σmν prior, with a uniform prior biasing results toward larger neutrino masses and higher H0, while a logarithmic prior reduces this bias significantly. Forecasts for the completed DESI BAO program, combined with Simons Observatory–like CMB lensing, next-generation 3 × 2 pt data, and expanded supernova samples predict σ(H0) ≃ 0.67 km s−1 Mpc−1 with fixed Σmν, and σ(H0) ≃ 1.1 km s−1 Mpc−1 with Σmν < 0.133 eV (<0.263 eV) at 68% (95%) confidence limit when Σmν is varied.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"15 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146205634","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 : 2026-02-16DOI: 10.3847/2041-8213/ae3da3
Alexandra Rochon, Étienne Artigau, Drew Weisserman, Lisa Dang, René Doyon, Charles Cadieux and Ryan Cloutier
We present a reanalysis of three 15 μm JWST/MIRI secondary eclipses of LHS 1140 c, a warm super-Earth (Rp = 1.272 R⊕) in a 3.78 day orbit around an M4.5 dwarf. We present a novel method for data reduction that leverages spatial derivatives of the point-spread function and compare it to widely used aperture photometry. Both methods yield an eclipse depth consistent within 1σ of the values reported in the literature. We measure an eclipse depth of 271 ppm corresponding to a brightness temperature of K, consistent with a bare rock. The secondary eclipse occurs 4.1 ± 0.8 minutes before the circular-orbit-predicted time. We explore the implications of our results on the internal structure of LHS 1140 c, the orbital architecture of the system, and the possibility of future observations with JWST. We find a core-mass fraction (CMF) informed by the stellar abundances of refractory elements of 0.34 ± 0.11, inflated compared to the CMF from radius and mass measurements, suggesting the possible presence of bulk volatiles in the interior.
{"title":"Reanalysis of the Eclipses of LHS 1140 c: No Evidence of an Atmosphere and Implications for the Internal Structure of the Planet","authors":"Alexandra Rochon, Étienne Artigau, Drew Weisserman, Lisa Dang, René Doyon, Charles Cadieux and Ryan Cloutier","doi":"10.3847/2041-8213/ae3da3","DOIUrl":"https://doi.org/10.3847/2041-8213/ae3da3","url":null,"abstract":"We present a reanalysis of three 15 μm JWST/MIRI secondary eclipses of LHS 1140 c, a warm super-Earth (Rp = 1.272 R⊕) in a 3.78 day orbit around an M4.5 dwarf. We present a novel method for data reduction that leverages spatial derivatives of the point-spread function and compare it to widely used aperture photometry. Both methods yield an eclipse depth consistent within 1σ of the values reported in the literature. We measure an eclipse depth of 271 ppm corresponding to a brightness temperature of K, consistent with a bare rock. The secondary eclipse occurs 4.1 ± 0.8 minutes before the circular-orbit-predicted time. We explore the implications of our results on the internal structure of LHS 1140 c, the orbital architecture of the system, and the possibility of future observations with JWST. We find a core-mass fraction (CMF) informed by the stellar abundances of refractory elements of 0.34 ± 0.11, inflated compared to the CMF from radius and mass measurements, suggesting the possible presence of bulk volatiles in the interior.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"5 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146210504","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 : 2026-02-16DOI: 10.3847/2041-8213/ae40aa
Katherine Panebianco, Minghao Yue, Anna-Christina Eilers, Xiaohui Fan, Feige Wang, Jinyi Yang and Robert A. Simcoe
We present JWST/NIRCam F070W and F480M imaging for a quasar at z = 5.07, J0025–0145, which is magnified by a foreground lensing galaxy. Existing Hubble Space Telescope (HST) imaging does not have sufficient spatial resolution to determine whether the background quasar is multiply imaged. Exploiting the sharp point-spread function (PSF) of the F070W band, we confirm that the background quasar can be well described by a single PSF, essentially ruling out the existence of multiple lensed images. We do not detect the quasar host galaxy in either the F070W or the F480M band. Using the HST and JWST photometry, we fit the spectral energy distribution of the foreground galaxy. The estimated mass ( ) and redshift ( ) of the foreground galaxy are consistent with a single-image lensing model. We estimate the maximum possible magnification of the quasar to be μmax = 3.2, which implies that the intrinsic Eddington ratio of the quasar is at least . Therefore, J0025–0145 has one of the highest Eddington ratios among z > 5 supermassive black holes known so far, suggesting the viability of super-Eddington growth for supermassive black holes in the early Universe.
{"title":"A Super-Eddington, Lensing-magnified Quasar at z = 5.07 Observed with JWST","authors":"Katherine Panebianco, Minghao Yue, Anna-Christina Eilers, Xiaohui Fan, Feige Wang, Jinyi Yang and Robert A. Simcoe","doi":"10.3847/2041-8213/ae40aa","DOIUrl":"https://doi.org/10.3847/2041-8213/ae40aa","url":null,"abstract":"We present JWST/NIRCam F070W and F480M imaging for a quasar at z = 5.07, J0025–0145, which is magnified by a foreground lensing galaxy. Existing Hubble Space Telescope (HST) imaging does not have sufficient spatial resolution to determine whether the background quasar is multiply imaged. Exploiting the sharp point-spread function (PSF) of the F070W band, we confirm that the background quasar can be well described by a single PSF, essentially ruling out the existence of multiple lensed images. We do not detect the quasar host galaxy in either the F070W or the F480M band. Using the HST and JWST photometry, we fit the spectral energy distribution of the foreground galaxy. The estimated mass ( ) and redshift ( ) of the foreground galaxy are consistent with a single-image lensing model. We estimate the maximum possible magnification of the quasar to be μmax = 3.2, which implies that the intrinsic Eddington ratio of the quasar is at least . Therefore, J0025–0145 has one of the highest Eddington ratios among z > 5 supermassive black holes known so far, suggesting the viability of super-Eddington growth for supermassive black holes in the early Universe.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146198644","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 : 2026-02-12DOI: 10.3847/2041-8213/ae3e8b
Andrzej A. Zdziarski, Swadesh Chand, Gulab Dewangan, Ranjeev Misra, Michał Szanecki, Bei You, Maxime Parra and Grégoire Marcel
We study the transient black hole binary MAXI J1631–479 observed simultaneously by NICER and NuSTAR in its soft spectral state. Its puzzling feature is the presence of a strong and broad Fe K line, while the continuum includes a prominent disk blackbody and a very weak power-law tail. The irradiation of the disk by a power-law spectrum fitting the tail is far too weak to explain the strong line. Previous proposals included the idea that the Fe K emission is intrinsic to the disk. Here, we propose that the strong line can be explained by the irradiation of the disk by photons from Comptonization of the disk blackbody by coronal electrons. One crucial effect is that the shape of the irradiating spectrum at ≲10 keV reflects that of the disk blackbody; it is strongly curved and has a higher flux than what would be produced by a fit with a power-law irradiation. The other effect is a relativistic enhancement of the backscattered coronal flux incident on the disk. Both effects together can account for the line, although the latter is modeled only quantitatively. While this result is independent of the physical model used for disk emission, the fitted spin depends heavily on that model. When employing a Kerr disk model for a thin disk with color correction, the fitted spin appears retrograde, rare for a Roche-lobe overflow binary. A model that accounts for both the finite thickness of the disk and radiative transfer yields a spin of a* ≈ 0.8–0.9.
{"title":"The Strong Fe K Line and Spin of the Black Hole X-Ray Binary MAXI J1631–479","authors":"Andrzej A. Zdziarski, Swadesh Chand, Gulab Dewangan, Ranjeev Misra, Michał Szanecki, Bei You, Maxime Parra and Grégoire Marcel","doi":"10.3847/2041-8213/ae3e8b","DOIUrl":"https://doi.org/10.3847/2041-8213/ae3e8b","url":null,"abstract":"We study the transient black hole binary MAXI J1631–479 observed simultaneously by NICER and NuSTAR in its soft spectral state. Its puzzling feature is the presence of a strong and broad Fe K line, while the continuum includes a prominent disk blackbody and a very weak power-law tail. The irradiation of the disk by a power-law spectrum fitting the tail is far too weak to explain the strong line. Previous proposals included the idea that the Fe K emission is intrinsic to the disk. Here, we propose that the strong line can be explained by the irradiation of the disk by photons from Comptonization of the disk blackbody by coronal electrons. One crucial effect is that the shape of the irradiating spectrum at ≲10 keV reflects that of the disk blackbody; it is strongly curved and has a higher flux than what would be produced by a fit with a power-law irradiation. The other effect is a relativistic enhancement of the backscattered coronal flux incident on the disk. Both effects together can account for the line, although the latter is modeled only quantitatively. While this result is independent of the physical model used for disk emission, the fitted spin depends heavily on that model. When employing a Kerr disk model for a thin disk with color correction, the fitted spin appears retrograde, rare for a Roche-lobe overflow binary. A model that accounts for both the finite thickness of the disk and radiative transfer yields a spin of a* ≈ 0.8–0.9.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"127 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146160308","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 : 2026-02-11DOI: 10.3847/2041-8213/ae3d34
Craig R. Walton, Maria Schönbächler, Heejin Jeon, Sen Hu, Alessandro Morbidelli, Thomas Bovay, Anne-Sophie Bouvier, Martin Whitehouse and Oliver Shorttle
The orbital elements of the solar system’s ancient asteroid families are highly dispersed, recording the last dynamical chaos in its history. However, dynamics alone cannot precisely date this when this terminal chaos occurred. Instead, we can precisely date the collisions triggered by such dynamical rearrangement to constrain this event. On planets, erosion, volcanism, and crustal recycling have removed almost all trace of rocks older than 4 Ga, erasing the archive of early solar system history. In contrast, the meteorite record generated by asteroid collisions represents a separate and more complete archive of the solar system’s early dynamical evolution. Here we build a record of in situ ordinary chondrite meteorite apatite U-Pb ages, sensitive to collisions that induce parent-body break-up events. We show that the U-Pb records of strongly shocked and weakly shocked meteorites are distinct. The U-Pb ages of weakly shocked meteorites record the decline of radiogenic heating in asteroidal bodies. Meanwhile, shocked meteorite ages record major collisions. All sampled ordinary chondrite bodies record collisions that occurred 4480 ± 20 Ma million years ago. No further multi-parent-body clusters of shock ages are found in this record until the very recent events that brought the meteorites to Earth. These ages constrain that the last date of major dynamical chaos to modify the orbital elements of asteroids occurred at around 4480 Ma. This date is relatively late in solar system history, possibly representing the timing of an orbital instability of the giant planets.
{"title":"Meteorite Radioisotope Ages Reveal Late Dynamical Chaos in the Solar System","authors":"Craig R. Walton, Maria Schönbächler, Heejin Jeon, Sen Hu, Alessandro Morbidelli, Thomas Bovay, Anne-Sophie Bouvier, Martin Whitehouse and Oliver Shorttle","doi":"10.3847/2041-8213/ae3d34","DOIUrl":"https://doi.org/10.3847/2041-8213/ae3d34","url":null,"abstract":"The orbital elements of the solar system’s ancient asteroid families are highly dispersed, recording the last dynamical chaos in its history. However, dynamics alone cannot precisely date this when this terminal chaos occurred. Instead, we can precisely date the collisions triggered by such dynamical rearrangement to constrain this event. On planets, erosion, volcanism, and crustal recycling have removed almost all trace of rocks older than 4 Ga, erasing the archive of early solar system history. In contrast, the meteorite record generated by asteroid collisions represents a separate and more complete archive of the solar system’s early dynamical evolution. Here we build a record of in situ ordinary chondrite meteorite apatite U-Pb ages, sensitive to collisions that induce parent-body break-up events. We show that the U-Pb records of strongly shocked and weakly shocked meteorites are distinct. The U-Pb ages of weakly shocked meteorites record the decline of radiogenic heating in asteroidal bodies. Meanwhile, shocked meteorite ages record major collisions. All sampled ordinary chondrite bodies record collisions that occurred 4480 ± 20 Ma million years ago. No further multi-parent-body clusters of shock ages are found in this record until the very recent events that brought the meteorites to Earth. These ages constrain that the last date of major dynamical chaos to modify the orbital elements of asteroids occurred at around 4480 Ma. This date is relatively late in solar system history, possibly representing the timing of an orbital instability of the giant planets.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"299 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146153535","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 : 2026-02-11DOI: 10.3847/2041-8213/ae3f32
Lulu Zhang, Chris Packham, Erin K. S. Hicks, Ric I. Davies, Daniel E. Delaney, Francoise Combes, Miguel Pereira-Santaella, Almudena Alonso-Herrero, Claudio Ricci, Omaira González-Martín, Laura Hermosa Muñoz, Ismael García- Bernete, Cristina Ramos Almeida, Dimitra Rigopoulou, Fergus R. Donnan, Enrica Bellocchi, Nancy A. Levenson, Martin J. Ward, Santiago García-Burillo and Sebastian F. Hoenig
This Letter presents an analysis of the infrared (∼3–28 μm) spectra extracted from the nuclear (r < 150 pc) regions of four low-luminosity active galactic nuclei (AGN), observed by JWST NIRSpec/integral field unit and MIRI/Medium Resolution Spectroscopy as an extension of the Galaxy Activity, Torus, and Outflow Survey. We find that, compared to higher-luminosity AGN, these low-luminosity AGN exhibit distinct properties in their emission of ionized gas, polycyclic aromatic hydrocarbons (PAHs), and molecular hydrogen (H2). Specifically, the low-luminosity AGN exhibit relatively weak high ionization potential lines (e.g., [Ne V] and [O IV]), and the line ratios suggest that fast radiative shocks (with vs of ∼100s km s−1) are the primary excitation source of ionized gas therein. Under the low-excitation conditions of their nuclear regions, these low-luminosity AGN generally exhibit a higher fraction of PAHs with large size (NC ≳ 200), reflecting the preferential destruction of smaller PAH molecules by AGN feedback. Furthermore, the H2 transitions in these low-luminosity AGN are not fully thermalized, with slow, plausibly jet-driven molecular shocks (with vs ≤ 10 km s−1) likely being the extra excitation source. Taken together with results from the literature, these findings indicate that feedback operates in both low- and high-luminosity AGN, although its impact varies with AGN luminosity. In particular, systematic variations in PAH band ratios are found across AGN, demonstrating the differing influence of feedback in AGN of varying luminosities and highlighting the potential of PAH band ratios as diagnostics for distinguishing kinetic- and radiative-mode AGN feedback.
本文介绍了从四个低亮度活动星系核（AGN）的核（r < 150pc）区域提取的红外（~ 3-28 μm）光谱的分析，这些光谱是由JWST NIRSpec/积分场单元和MIRI/中分辨率光谱观测到的，作为星系活动、环面和流出量调查的延伸。我们发现，与高亮度AGN相比，这些低亮度AGN在电离气体、多环芳烃（PAHs）和分子氢（H2）的发射方面表现出不同的特性。具体来说，低亮度AGN表现出相对较弱的高电离势线（例如[Ne V]和[O IV]），线比表明，快速辐射冲击（vs为~ 100 km s−1）是其中电离气体的主要激发源。在核区低激发条件下，这些低亮度AGN通常具有较高比例的大尺寸PAHs (NC > 200)，反映了AGN反馈优先破坏较小的PAH分子。此外，这些低亮度AGN中的H2跃迁没有完全热化，可能是额外的激发源，可能是缓慢的，似乎是射流驱动的分子激波（vs≤10 km s−1）。结合文献的结果，这些发现表明反馈在低亮度和高亮度AGN中都起作用，尽管其影响随AGN亮度而变化。特别是，在AGN中发现了多环芳烃带比的系统性变化，证明了不同亮度的AGN中反馈的不同影响，并突出了多环芳烃带比作为区分动力学模式和辐射模式AGN反馈的诊断潜力。
{"title":"Evidence of Feedback Effects in Low-luminosity Active Galactic Nuclei Revealed by JWST Spectroscopy","authors":"Lulu Zhang, Chris Packham, Erin K. S. Hicks, Ric I. Davies, Daniel E. Delaney, Francoise Combes, Miguel Pereira-Santaella, Almudena Alonso-Herrero, Claudio Ricci, Omaira González-Martín, Laura Hermosa Muñoz, Ismael García- Bernete, Cristina Ramos Almeida, Dimitra Rigopoulou, Fergus R. Donnan, Enrica Bellocchi, Nancy A. Levenson, Martin J. Ward, Santiago García-Burillo and Sebastian F. Hoenig","doi":"10.3847/2041-8213/ae3f32","DOIUrl":"https://doi.org/10.3847/2041-8213/ae3f32","url":null,"abstract":"This Letter presents an analysis of the infrared (∼3–28 μm) spectra extracted from the nuclear (r < 150 pc) regions of four low-luminosity active galactic nuclei (AGN), observed by JWST NIRSpec/integral field unit and MIRI/Medium Resolution Spectroscopy as an extension of the Galaxy Activity, Torus, and Outflow Survey. We find that, compared to higher-luminosity AGN, these low-luminosity AGN exhibit distinct properties in their emission of ionized gas, polycyclic aromatic hydrocarbons (PAHs), and molecular hydrogen (H2). Specifically, the low-luminosity AGN exhibit relatively weak high ionization potential lines (e.g., [Ne V] and [O IV]), and the line ratios suggest that fast radiative shocks (with vs of ∼100s km s−1) are the primary excitation source of ionized gas therein. Under the low-excitation conditions of their nuclear regions, these low-luminosity AGN generally exhibit a higher fraction of PAHs with large size (NC ≳ 200), reflecting the preferential destruction of smaller PAH molecules by AGN feedback. Furthermore, the H2 transitions in these low-luminosity AGN are not fully thermalized, with slow, plausibly jet-driven molecular shocks (with vs ≤ 10 km s−1) likely being the extra excitation source. Taken together with results from the literature, these findings indicate that feedback operates in both low- and high-luminosity AGN, although its impact varies with AGN luminosity. In particular, systematic variations in PAH band ratios are found across AGN, demonstrating the differing influence of feedback in AGN of varying luminosities and highlighting the potential of PAH band ratios as diagnostics for distinguishing kinetic- and radiative-mode AGN feedback.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"4 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146153538","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 : 2026-02-11DOI: 10.3847/2041-8213/ae3f2b
David Berardo, Julien de Wit, Michael Gillon, Ward S. Howard, Vincent Bourrier, Emeline Bolmont, Matthew W. Cotton, Florian Quatresooz, Léonie Hoerner, Artem Burdanov, Adam J. Burgasser, Brice-Olivier Demory, David Ehrenreich, Susan M. Lederer, Benjamin V. Rackham, Sara Seager and Amaury Triaud
Lyα observations provide a powerful probe of stellar activity and atmospheric escape in exoplanetary systems. We present here an analysis of 109 Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph (STIS) orbits monitoring the TRAPPIST-1 system between 2017 and 2022, covering three to five transits for each of its seven planets. We rule out transit depths ≳30%, prompting a revision of atmospheric escape rates, with upper limits larger than previously reported (e.g., Earth-ocean-equivalent hydrogen content per Gyr for planet b, consistent with claims that it is airless). The transit depth upper limits are ∼3 times larger than expected from the photon noise owing to a large baseline scatter, which we link to TRAPPIST-1’s intrinsic Lyα variability from frequent “microflares.” While JWST’s near-infrared observations have shown that ∼1030 erg flares occur every ∼6 hr, we identify ∼1029 erg flares on subhour timescales in both HST/STIS and Very Large Telescope observations. The far-UV and optical amplitudes (∼400% vs. ∼3%, respectively) for flares with similar waiting times indicate flare temperatures of 9700 K over 0.017 % of the stellar disk. Finally, our multiyear baseline reveals a variability with P = 3.27 ± 0.04 days—the first independent validation of TRAPPIST-1’s 3.3-day rotation period.
{"title":"Hubble’s Multiyear Search for Exospheres in the TRAPPIST-1 System Reveals Frequent Microflares","authors":"David Berardo, Julien de Wit, Michael Gillon, Ward S. Howard, Vincent Bourrier, Emeline Bolmont, Matthew W. Cotton, Florian Quatresooz, Léonie Hoerner, Artem Burdanov, Adam J. Burgasser, Brice-Olivier Demory, David Ehrenreich, Susan M. Lederer, Benjamin V. Rackham, Sara Seager and Amaury Triaud","doi":"10.3847/2041-8213/ae3f2b","DOIUrl":"https://doi.org/10.3847/2041-8213/ae3f2b","url":null,"abstract":"Lyα observations provide a powerful probe of stellar activity and atmospheric escape in exoplanetary systems. We present here an analysis of 109 Hubble Space Telescope (HST)/Space Telescope Imaging Spectrograph (STIS) orbits monitoring the TRAPPIST-1 system between 2017 and 2022, covering three to five transits for each of its seven planets. We rule out transit depths ≳30%, prompting a revision of atmospheric escape rates, with upper limits larger than previously reported (e.g., Earth-ocean-equivalent hydrogen content per Gyr for planet b, consistent with claims that it is airless). The transit depth upper limits are ∼3 times larger than expected from the photon noise owing to a large baseline scatter, which we link to TRAPPIST-1’s intrinsic Lyα variability from frequent “microflares.” While JWST’s near-infrared observations have shown that ∼1030 erg flares occur every ∼6 hr, we identify ∼1029 erg flares on subhour timescales in both HST/STIS and Very Large Telescope observations. The far-UV and optical amplitudes (∼400% vs. ∼3%, respectively) for flares with similar waiting times indicate flare temperatures of 9700 K over 0.017 % of the stellar disk. Finally, our multiyear baseline reveals a variability with P = 3.27 ± 0.04 days—the first independent validation of TRAPPIST-1’s 3.3-day rotation period.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"25 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146153537","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 : 2026-02-11DOI: 10.3847/2041-8213/ae3d32
Giuseppe Consolini and Elettra Consolini
A notable feature of turbulence in solar wind is the presence of an additional power-law spectral domain at scales below the ion inertial length. This spectral domain has been attributed to a distinct turbulent regime involving alternative wave modes. However, this interpretation is still up for debate, as is the occurrence of dissipation at these scales. Here, we present a methodology to investigate the irreversible dynamics and the lack of detailed balance for the energy of magnetic field fluctuations at ion/sub-ion scales via the asymmetric time-correlation function using high-resolution magnetic field measurements from the Parker Solar Probe mission. The preliminary results are discussed in relation to irreversibility and dissipation at ion/sub-ion scales.
{"title":"Lack of Detailed Balance at Sub-ion Scales in Turbulent Solar Wind","authors":"Giuseppe Consolini and Elettra Consolini","doi":"10.3847/2041-8213/ae3d32","DOIUrl":"https://doi.org/10.3847/2041-8213/ae3d32","url":null,"abstract":"A notable feature of turbulence in solar wind is the presence of an additional power-law spectral domain at scales below the ion inertial length. This spectral domain has been attributed to a distinct turbulent regime involving alternative wave modes. However, this interpretation is still up for debate, as is the occurrence of dissipation at these scales. Here, we present a methodology to investigate the irreversible dynamics and the lack of detailed balance for the energy of magnetic field fluctuations at ion/sub-ion scales via the asymmetric time-correlation function using high-resolution magnetic field measurements from the Parker Solar Probe mission. The preliminary results are discussed in relation to irreversibility and dissipation at ion/sub-ion scales.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"86 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146153504","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 : 2026-02-11DOI: 10.3847/2041-8213/ae3d39
Jiadong Li, 佳东 李, Hans-Walter Rix, Yuan-Sen Ting, Yu-Ting Wang, Szabolcs Mészáros, Ilija Medan, Chao Liu, Zhiqiang Yan, Peter J. Smith, Dan Qiu, Alexandre Roman-Lopes, Gregory M. Green, Danny Horta, Zachary Way, Tadafumi Matsuno, Stefano O. Souza and José G. Fernández-Trincado
We present the first determination of the Galactic stellar mass function (MF) for low-mass stars (0.2–0.5 M⊙) at metallicities [Fe/H] ≲ −1. A sample of ∼53,000 stars was selected as metal-poor on the basis of both their halolike orbits and their spectroscopic [Fe/H] from Gaia DR3 BP/RP (XP) spectra. These metallicity estimates for low-mass stars were enabled by calibrating Gaia XP spectra with stellar parameters from SDSS-V. For −1.5 < [Fe/H] < −1, we find that the MF below 0.5 M⊙ exhibits a “bottom-heavy” power-law slope of α ∼ −1.6. We tentatively find that at even lower metallicities the MF becomes very bottom-light, with a near-flat power-law slope of α ∼ 0 that implies a severe deficit of low-mass stars. This metallicity-dependent variation is insensitive to the adopted stellar evolution model. These results show that the Galactic low-mass MF is not universal, with variations in the metal-poor regime. A further calibration of XP metallicities in the regime of M < 0.5 M⊙ and [Fe/H] < −1.5 will be essential to verify these tentative low-metallicity trends.
{"title":"Variations in the Milky Way’s Stellar Mass Function at [Fe/H] < −1","authors":"Jiadong Li, 佳东 李, Hans-Walter Rix, Yuan-Sen Ting, Yu-Ting Wang, Szabolcs Mészáros, Ilija Medan, Chao Liu, Zhiqiang Yan, Peter J. Smith, Dan Qiu, Alexandre Roman-Lopes, Gregory M. Green, Danny Horta, Zachary Way, Tadafumi Matsuno, Stefano O. Souza and José G. Fernández-Trincado","doi":"10.3847/2041-8213/ae3d39","DOIUrl":"https://doi.org/10.3847/2041-8213/ae3d39","url":null,"abstract":"We present the first determination of the Galactic stellar mass function (MF) for low-mass stars (0.2–0.5 M⊙) at metallicities [Fe/H] ≲ −1. A sample of ∼53,000 stars was selected as metal-poor on the basis of both their halolike orbits and their spectroscopic [Fe/H] from Gaia DR3 BP/RP (XP) spectra. These metallicity estimates for low-mass stars were enabled by calibrating Gaia XP spectra with stellar parameters from SDSS-V. For −1.5 < [Fe/H] < −1, we find that the MF below 0.5 M⊙ exhibits a “bottom-heavy” power-law slope of α ∼ −1.6. We tentatively find that at even lower metallicities the MF becomes very bottom-light, with a near-flat power-law slope of α ∼ 0 that implies a severe deficit of low-mass stars. This metallicity-dependent variation is insensitive to the adopted stellar evolution model. These results show that the Galactic low-mass MF is not universal, with variations in the metal-poor regime. A further calibration of XP metallicities in the regime of M < 0.5 M⊙ and [Fe/H] < −1.5 will be essential to verify these tentative low-metallicity trends.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146153536","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 : 2026-02-11DOI: 10.3847/2041-8213/ae382a
Jorge A. Zavala, Andreas L. Faisst, Manuel Aravena, Caitlin M. Casey, Jeyhan S. Kartaltepe, Felix Martinez, John D. Silverman, Sune Toft, Ezequiel Treister, Hollis B. Akins, Hiddo Algera, Karina Barboza, Andrew J. Battisti, Gabriel Brammer, Zheng Cai, Jaclyn Champagne, Nicole E. Drakos, Eiichi Egami, Xiaohui Fan, Maximilien Franco, Yoshinobu Fudamoto, Seiji Fujimoto, Steven Gillman, Ghassem Gozaliasl, Santosh Harish, Xiangyu Jin, Koki Kakiichi, Darshan Kakkad, Anton M. Koekemoer, Ruqiu Lin, Daizhong Liu, Arianna S. Long, Georgios E. Magdis, Sinclaire Manning, Crystal L. Martin, Jed McKinney, Romain Meyer, Giulia Rodighiero, Victoria Salazar, David B. Sanders, Marko Shuntov, Margherita Talia, Takumi S. Tanaka, Feige Wang, Wuji Wang, Stephen M. Wilkins, Jinyi Yang, Min S. Yun and The CHAMPS and COSMOS-Web collaborations
We exploit a new sample of around 400 bright dusty galaxies from the Atacama Large Millimeter/submillimeter Array (ALMA) CHAMPS Large Program, together with the rich JWST multiband data products in the COSMOS field, to explore and validate new selection methods for identifying dusty star-forming galaxies (DSFGs). Here we present an effective empirical selection criterion based on a newly defined parameter: . Incorporating the m277W − m444W color as a second parameter further improves the purity of the selection. We then apply this method to the COSMOS2025 catalog to search for fainter dusty galaxy candidates below the ALMA CHAMPS detection limit and, through a stacking technique, identify a population of high-redshift DSFG candidates with an average flux density of S1.2mm ≈ 150 μJy and a space density of ∼6 × 10−6 Mpc−3. Three of these galaxies have been spectroscopically confirmed at zspec = 7.20, 5.85, and 5.04. This faint population seems to have been missed by most of the previous submillimeter/millimeter surveys and ground- and space-based UV−near-IR observations. We then show evidence of a possible evolutionary connection between the z > 10 UV-bright galaxies recently discovered by JWST, the faint dusty z ≈ 6-8 galaxies identified here, and the population of z ≈ 3–5 massive quiescent galaxies; all of them are potentially linked as progenitor−descendant populations based on their abundance, redshifts, and stellar masses. Future spectroscopic campaigns will be essential to confirm the redshifts and physical properties of these massive, faint, high-redshift DSFG candidates.
{"title":"ALMA and JWST Identification of Faint Dusty Star-forming Galaxies up to z ∼ 8 and Their Connection with Other Galaxy Populations","authors":"Jorge A. Zavala, Andreas L. Faisst, Manuel Aravena, Caitlin M. Casey, Jeyhan S. Kartaltepe, Felix Martinez, John D. Silverman, Sune Toft, Ezequiel Treister, Hollis B. Akins, Hiddo Algera, Karina Barboza, Andrew J. Battisti, Gabriel Brammer, Zheng Cai, Jaclyn Champagne, Nicole E. Drakos, Eiichi Egami, Xiaohui Fan, Maximilien Franco, Yoshinobu Fudamoto, Seiji Fujimoto, Steven Gillman, Ghassem Gozaliasl, Santosh Harish, Xiangyu Jin, Koki Kakiichi, Darshan Kakkad, Anton M. Koekemoer, Ruqiu Lin, Daizhong Liu, Arianna S. Long, Georgios E. Magdis, Sinclaire Manning, Crystal L. Martin, Jed McKinney, Romain Meyer, Giulia Rodighiero, Victoria Salazar, David B. Sanders, Marko Shuntov, Margherita Talia, Takumi S. Tanaka, Feige Wang, Wuji Wang, Stephen M. Wilkins, Jinyi Yang, Min S. Yun and The CHAMPS and COSMOS-Web collaborations","doi":"10.3847/2041-8213/ae382a","DOIUrl":"https://doi.org/10.3847/2041-8213/ae382a","url":null,"abstract":"We exploit a new sample of around 400 bright dusty galaxies from the Atacama Large Millimeter/submillimeter Array (ALMA) CHAMPS Large Program, together with the rich JWST multiband data products in the COSMOS field, to explore and validate new selection methods for identifying dusty star-forming galaxies (DSFGs). Here we present an effective empirical selection criterion based on a newly defined parameter: . Incorporating the m277W − m444W color as a second parameter further improves the purity of the selection. We then apply this method to the COSMOS2025 catalog to search for fainter dusty galaxy candidates below the ALMA CHAMPS detection limit and, through a stacking technique, identify a population of high-redshift DSFG candidates with an average flux density of S1.2mm ≈ 150 μJy and a space density of ∼6 × 10−6 Mpc−3. Three of these galaxies have been spectroscopically confirmed at zspec = 7.20, 5.85, and 5.04. This faint population seems to have been missed by most of the previous submillimeter/millimeter surveys and ground- and space-based UV−near-IR observations. We then show evidence of a possible evolutionary connection between the z > 10 UV-bright galaxies recently discovered by JWST, the faint dusty z ≈ 6-8 galaxies identified here, and the population of z ≈ 3–5 massive quiescent galaxies; all of them are potentially linked as progenitor−descendant populations based on their abundance, redshifts, and stellar masses. Future spectroscopic campaigns will be essential to confirm the redshifts and physical properties of these massive, faint, high-redshift DSFG candidates.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2026-02-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146153503","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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