Pub Date : 2025-02-10DOI: 10.3847/2041-8213/adacea
Hayley A. Bunn, Silvia Spezzano, Laurent H. Coudert, Jean-Claude Guillemin, Yuxin Lin, Christian P. Endres, Brant Billinghurst, Olivier Pirali, Jes Jørgensen, Valerio Lattanzi and Paola Caselli
We report an extensive rotational spectroscopic analysis of singly deuterated methyl mercaptan (CH2DSH) using both millimeter and far-infrared synchrotron spectra to achieve a global torsional analysis of the three lowest torsional substates (e0, e1, and o1) of this nonrigid species. A fit including 3419 millimeter-wave transitions along with 43 infrared torsional subband centers was performed with rms deviations of 0.233 MHz and 0.270 cm−1, respectively, resulting in 68 fit parameters. A spectroscopic catalog built from this analysis for a temperature of 125 K has led to the first interstellar detection of CH2DSH toward the solar-like protostar IRAS 16293-2422 B. We report the identification of 46 transitions, including eight relatively unblended lines, resulting in a derived column density of (3.0 ± 0.3) × 1014 cm−2. The column density ratio for HDCS/CH2DSH compared to HDCO/CH2DOH suggests a difference in the interstellar chemistry between the sulfur and oxygen complex organics, in particular a different link between H2CO and CH3OH and between H2CS and CH3SH. This is the first interstellar detection of a deuterated sulfur-bearing complex organic molecule and therefore an important step toward understanding the chemical origin of sulfur-based prebiotics.
{"title":"Laboratory Rotational Spectroscopy Leads to the First Interstellar Detection of Singly Deuterated Methyl Mercaptan (CH2DSH)","authors":"Hayley A. Bunn, Silvia Spezzano, Laurent H. Coudert, Jean-Claude Guillemin, Yuxin Lin, Christian P. Endres, Brant Billinghurst, Olivier Pirali, Jes Jørgensen, Valerio Lattanzi and Paola Caselli","doi":"10.3847/2041-8213/adacea","DOIUrl":"https://doi.org/10.3847/2041-8213/adacea","url":null,"abstract":"We report an extensive rotational spectroscopic analysis of singly deuterated methyl mercaptan (CH2DSH) using both millimeter and far-infrared synchrotron spectra to achieve a global torsional analysis of the three lowest torsional substates (e0, e1, and o1) of this nonrigid species. A fit including 3419 millimeter-wave transitions along with 43 infrared torsional subband centers was performed with rms deviations of 0.233 MHz and 0.270 cm−1, respectively, resulting in 68 fit parameters. A spectroscopic catalog built from this analysis for a temperature of 125 K has led to the first interstellar detection of CH2DSH toward the solar-like protostar IRAS 16293-2422 B. We report the identification of 46 transitions, including eight relatively unblended lines, resulting in a derived column density of (3.0 ± 0.3) × 1014 cm−2. The column density ratio for HDCS/CH2DSH compared to HDCO/CH2DOH suggests a difference in the interstellar chemistry between the sulfur and oxygen complex organics, in particular a different link between H2CO and CH3OH and between H2CS and CH3SH. This is the first interstellar detection of a deuterated sulfur-bearing complex organic molecule and therefore an important step toward understanding the chemical origin of sulfur-based prebiotics.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143384975","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 : 2025-02-10DOI: 10.3847/2041-8213/adae9d
Amy Furniss, Josepf N. Amador, Olivier Hervet, Ollie Jackson and David A. Williams
The large-scale universal structure comprises strands of dark matter and galaxies with large underdense volumes known as voids. We measure the fraction of the line of sight that intersects voids for active galactic nuclei (AGN) detected by Fermi Large Area Telescope (LAT) and quasars from the Sloan Digital Sky Survey (SDSS). This “voidiness” fraction is a rudimentary proxy for the density along the line of sight to the galaxies. The voidiness of SDSS-observed quasars (QSOs) is distinctly different from randomly distributed source populations, with a median p-value of 4.6 × 10−5 and ≪1 × 10−7, when compared with 500 simulated populations with randomly simulated locations but matching redshifts in the 0.1 ≤ z < 0.4 and 0.4 ≤ z < 0.7 intervals, respectively. A similar comparison of the voidiness for LAT-detected AGN shows median p-values greater than 0.05 in each redshift interval. When comparing the SDSS QSO population to the LAT-detected AGN, we mitigate potential bias from a relationship between redshift and voidiness by comparing the LAT-detected AGN to a “redshift-matched” set of SDSS QSOs. The LAT-detected AGN between a redshift of 0.4 and 0.7 show higher voidiness compared to the redshift-matched SDSS QSO populations, with a median p-value of 2.3 × 10−5 (a 4.1σ deviation). No deviation is found when comparing the same populations between redshifts of 0.1 and 0.4 (p > 0.05). We do not study possible causes of this voidiness difference. It might relate to propagation effects from lower magnetic or radiative background fields within voids or to an environment more favorable for gamma-ray production for AGN near voids.
{"title":"A Study on the Line of Sight to Galaxies Detected at Gamma-Ray Energies","authors":"Amy Furniss, Josepf N. Amador, Olivier Hervet, Ollie Jackson and David A. Williams","doi":"10.3847/2041-8213/adae9d","DOIUrl":"https://doi.org/10.3847/2041-8213/adae9d","url":null,"abstract":"The large-scale universal structure comprises strands of dark matter and galaxies with large underdense volumes known as voids. We measure the fraction of the line of sight that intersects voids for active galactic nuclei (AGN) detected by Fermi Large Area Telescope (LAT) and quasars from the Sloan Digital Sky Survey (SDSS). This “voidiness” fraction is a rudimentary proxy for the density along the line of sight to the galaxies. The voidiness of SDSS-observed quasars (QSOs) is distinctly different from randomly distributed source populations, with a median p-value of 4.6 × 10−5 and ≪1 × 10−7, when compared with 500 simulated populations with randomly simulated locations but matching redshifts in the 0.1 ≤ z < 0.4 and 0.4 ≤ z < 0.7 intervals, respectively. A similar comparison of the voidiness for LAT-detected AGN shows median p-values greater than 0.05 in each redshift interval. When comparing the SDSS QSO population to the LAT-detected AGN, we mitigate potential bias from a relationship between redshift and voidiness by comparing the LAT-detected AGN to a “redshift-matched” set of SDSS QSOs. The LAT-detected AGN between a redshift of 0.4 and 0.7 show higher voidiness compared to the redshift-matched SDSS QSO populations, with a median p-value of 2.3 × 10−5 (a 4.1σ deviation). No deviation is found when comparing the same populations between redshifts of 0.1 and 0.4 (p > 0.05). We do not study possible causes of this voidiness difference. It might relate to propagation effects from lower magnetic or radiative background fields within voids or to an environment more favorable for gamma-ray production for AGN near voids.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"12 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143384977","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 : 2025-02-10DOI: 10.3847/2041-8213/adaeb9
Ning Jiang, Di Luo, Jiazheng Zhu and Roc M. Cutri
PS16dtm is one of the earliest reported tidal disruption events (TDEs) in active galactic nuclei and displays a remarkably bright and long-lived infrared (IR) echo revealed by multiepoch photometry from the Wide-field Infrared Survey Explorer (WISE). After a rapid rise in the first year, the echo remains persistently at a high state from 2017 July to 2024 July, the latest epoch, and keeps an almost constant color. We have fitted the extraordinary IR emission with a refined dust echo model by taking into account the dust sublimation process. The fitting suggests that an extremely giant dust structure with a new inner radius of ∼1.6 pc and an ultrahigh peak bolometric luminosity, i.e., ∼6 × 1046 erg s−1 for typical 0.1 μm-sized silicate grain, is required to account for the IR echo. This work highlights the distinctive value of IR echoes in measuring the accurate intrinsic bolometric luminosity and thus the total radiated energy of TDEs, which could be severely underestimated by traditional methods, i.e., probably by more than 1 order of magnitude in PS16dtm. Such large energetic output compared to normal TDEs could be boosted by the preexisting accretion disk and gas clouds around the black hole. Our model can be validated in the near future by IR time-domain surveys such as the Near-Earth Object Surveyor, given the recent retirement of WISE. In addition, the potential for spatially resolving a receding dusty torus after a TDE could also be an exciting subject in the era of advanced IR interferometry.
{"title":"The Extraordinary Long-lasting Infrared Echo of PS16dtm Reveals an Extremely Energetic Nuclear Outburst","authors":"Ning Jiang, Di Luo, Jiazheng Zhu and Roc M. Cutri","doi":"10.3847/2041-8213/adaeb9","DOIUrl":"https://doi.org/10.3847/2041-8213/adaeb9","url":null,"abstract":"PS16dtm is one of the earliest reported tidal disruption events (TDEs) in active galactic nuclei and displays a remarkably bright and long-lived infrared (IR) echo revealed by multiepoch photometry from the Wide-field Infrared Survey Explorer (WISE). After a rapid rise in the first year, the echo remains persistently at a high state from 2017 July to 2024 July, the latest epoch, and keeps an almost constant color. We have fitted the extraordinary IR emission with a refined dust echo model by taking into account the dust sublimation process. The fitting suggests that an extremely giant dust structure with a new inner radius of ∼1.6 pc and an ultrahigh peak bolometric luminosity, i.e., ∼6 × 1046 erg s−1 for typical 0.1 μm-sized silicate grain, is required to account for the IR echo. This work highlights the distinctive value of IR echoes in measuring the accurate intrinsic bolometric luminosity and thus the total radiated energy of TDEs, which could be severely underestimated by traditional methods, i.e., probably by more than 1 order of magnitude in PS16dtm. Such large energetic output compared to normal TDEs could be boosted by the preexisting accretion disk and gas clouds around the black hole. Our model can be validated in the near future by IR time-domain surveys such as the Near-Earth Object Surveyor, given the recent retirement of WISE. In addition, the potential for spatially resolving a receding dusty torus after a TDE could also be an exciting subject in the era of advanced IR interferometry.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"65 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143384978","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 : 2025-02-07DOI: 10.3847/2041-8213/adad73
Francisco C. De Gerónimo, Murat Uzundag, Alberto Rebassa-Mansergas, Alex Brown, Mukremin Kilic, Alejandro H. Córsico, Gracyn C. Jewett and Adam G. Moss
The discovery of pulsations in ultramassive (UM) white dwarfs (WDs) can help to probe their interiors and unveil their core composition and crystallized mass fraction through asteroseismic techniques. To date, the richest pulsating UM WD known is BPM 37093 with 8 modes detected, for which detailed asteroseismic analysis has been performed in the past. In this work, we report the discovery of 19 pulsation modes in the UM WD star WD J0135+5722, making it the richest pulsating hydrogen-atmosphere UM WD known to date. This object exhibits multiperiodic luminosity variations with periods ranging from 137 to 1345 s, typical of pulsating WDs in the ZZ Ceti instability strip, which is centered at Teff ∼ 12,000 K. We estimate the stellar mass of WD J0135+5722 by different methods, resulting in M⋆ ∼ 1.12–1.14 M⊙ if the star’s core is made of oxygen and neon or M⋆ ∼ 1.14–1.15 M⊙ if the star hosts a carbon oxygen core. Future analysis of the star periods could shed light on the core chemical composition through asteroseismology.
{"title":"Discovery of the Richest Pulsating Ultramassive White Dwarf","authors":"Francisco C. De Gerónimo, Murat Uzundag, Alberto Rebassa-Mansergas, Alex Brown, Mukremin Kilic, Alejandro H. Córsico, Gracyn C. Jewett and Adam G. Moss","doi":"10.3847/2041-8213/adad73","DOIUrl":"https://doi.org/10.3847/2041-8213/adad73","url":null,"abstract":"The discovery of pulsations in ultramassive (UM) white dwarfs (WDs) can help to probe their interiors and unveil their core composition and crystallized mass fraction through asteroseismic techniques. To date, the richest pulsating UM WD known is BPM 37093 with 8 modes detected, for which detailed asteroseismic analysis has been performed in the past. In this work, we report the discovery of 19 pulsation modes in the UM WD star WD J0135+5722, making it the richest pulsating hydrogen-atmosphere UM WD known to date. This object exhibits multiperiodic luminosity variations with periods ranging from 137 to 1345 s, typical of pulsating WDs in the ZZ Ceti instability strip, which is centered at Teff ∼ 12,000 K. We estimate the stellar mass of WD J0135+5722 by different methods, resulting in M⋆ ∼ 1.12–1.14 M⊙ if the star’s core is made of oxygen and neon or M⋆ ∼ 1.14–1.15 M⊙ if the star hosts a carbon oxygen core. Future analysis of the star periods could shed light on the core chemical composition through asteroseismology.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"47 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143258002","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 : 2025-02-07DOI: 10.3847/2041-8213/adad61
Sam Rose, Ryan M. Lau, Jacob E. Jencson, Mansi M. Kasliwal, Kishalay De, Michael E. Ressler, Ori D. Fox and Matthew J. Hankins
The James Webb Space Telescope (JWST) has opened up a new window to study highly reddened explosive transients. We present results from late-time JWST follow-up spectroscopic observations with NIRSpec and MIRI-LRS of the intermediate-luminosity red transient (ILRT) AT 2019abn. ILRTs represent a mysterious class of transients that exhibit peak luminosities between those of classical novae and supernovae and that are known to be highly dust obscured. Similar to the prototypical examples of this class of objects, NGC 300 2008-OT and SN 2008S, AT 2019abn has an extremely red and dusty progenitor detected only in pre-explosion Spitzer/IRAC imaging at 3.6 and 4.5 μm and not in deep optical or near-infrared Hubble Space Telescope images. We find that late-time observations of AT 2019abn from NEOWISE and JWST are consistent with the late-time evolution of SN 2008S. In part because they are so obscured by dust, it is unknown what produces an ILRT, with hypotheses including high-mass stellar merger events, nonterminal stellar outbursts, and terminal supernova explosions through electron capture in super-AGB (SAGB) stars. Our JWST observations show strong mid-IR class C polycyclic aromatic hydrocarbon features at 6.3 and 8.25 μm typical of carbon-rich post-AGB sources. These features suggest that the dust around AT 2019abn is composed of carbonaceous grains, which are not typically observed around red supergiants. However, depending on the strength and temperature of hot bottom burning, SAGB stars may be expected to exhibit a carbon-rich chemistry. Thus, our JWST observations are consistent with AT 2019abn having an SAGB progenitor and exploding as an electron-capture supernova.
{"title":"Investigating the Electron-capture Supernova Candidate AT 2019abn with JWST Spectroscopy","authors":"Sam Rose, Ryan M. Lau, Jacob E. Jencson, Mansi M. Kasliwal, Kishalay De, Michael E. Ressler, Ori D. Fox and Matthew J. Hankins","doi":"10.3847/2041-8213/adad61","DOIUrl":"https://doi.org/10.3847/2041-8213/adad61","url":null,"abstract":"The James Webb Space Telescope (JWST) has opened up a new window to study highly reddened explosive transients. We present results from late-time JWST follow-up spectroscopic observations with NIRSpec and MIRI-LRS of the intermediate-luminosity red transient (ILRT) AT 2019abn. ILRTs represent a mysterious class of transients that exhibit peak luminosities between those of classical novae and supernovae and that are known to be highly dust obscured. Similar to the prototypical examples of this class of objects, NGC 300 2008-OT and SN 2008S, AT 2019abn has an extremely red and dusty progenitor detected only in pre-explosion Spitzer/IRAC imaging at 3.6 and 4.5 μm and not in deep optical or near-infrared Hubble Space Telescope images. We find that late-time observations of AT 2019abn from NEOWISE and JWST are consistent with the late-time evolution of SN 2008S. In part because they are so obscured by dust, it is unknown what produces an ILRT, with hypotheses including high-mass stellar merger events, nonterminal stellar outbursts, and terminal supernova explosions through electron capture in super-AGB (SAGB) stars. Our JWST observations show strong mid-IR class C polycyclic aromatic hydrocarbon features at 6.3 and 8.25 μm typical of carbon-rich post-AGB sources. These features suggest that the dust around AT 2019abn is composed of carbonaceous grains, which are not typically observed around red supergiants. However, depending on the strength and temperature of hot bottom burning, SAGB stars may be expected to exhibit a carbon-rich chemistry. Thus, our JWST observations are consistent with AT 2019abn having an SAGB progenitor and exploding as an electron-capture supernova.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"21 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143367246","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 : 2025-02-06DOI: 10.3847/2041-8213/ad9609
Anniek J. Gloudemans, Frits Sweijen, Leah K. Morabito, Emanuele Paolo Farina, Kenneth J. Duncan, Yuichi Harikane, Huub J. A. Röttgering, Aayush Saxena and Jan-Torge Schindler
We present the discovery of a large extended radio jet associated with the extremely radio-loud quasar J1601+3102 at z ∼ 5 from subarcsecond resolution imaging at 144 MHz with the International LOFAR Telescope. These large radio lobes have been argued to remain elusive at z > 4 due to energy losses in the synchrotron emitting plasma as a result of scattering of the strong cosmic microwave background at these high redshifts. Nonetheless, the 0 3 resolution radio image of J1601+3102 reveals a northern and a southern radio lobe located at 9 and 57 kpc from the optical quasar, respectively. The measured jet size of 66 kpc makes J1601+3102 the largest extended radio jet at z > 4 to date. However, it is expected to have an even larger physical size in reality due to projection effects brought about by the viewing angle. Furthermore, we observe the rest-frame UV spectrum of J1601+3102 with Gemini/GNIRS to examine its black hole properties, which results in a mass of 4.5 × 108M⊙ with an Eddington luminosity ratio of 0.45. The black hole mass is relatively low compared to the known high-z quasar population, which suggests that a high black hole mass is not strictly necessary to generate a powerful jet. This discovery of the first ∼100 kpc radio jet at z > 4 shows that these objects exist despite energy losses from inverse Compton scattering and can put invaluable constraints on the formation of the first radio-loud sources in the early Universe.
{"title":"Monster Radio Jet (>66 kpc) Observed in Quasar at z ∼ 5","authors":"Anniek J. Gloudemans, Frits Sweijen, Leah K. Morabito, Emanuele Paolo Farina, Kenneth J. Duncan, Yuichi Harikane, Huub J. A. Röttgering, Aayush Saxena and Jan-Torge Schindler","doi":"10.3847/2041-8213/ad9609","DOIUrl":"https://doi.org/10.3847/2041-8213/ad9609","url":null,"abstract":"We present the discovery of a large extended radio jet associated with the extremely radio-loud quasar J1601+3102 at z ∼ 5 from subarcsecond resolution imaging at 144 MHz with the International LOFAR Telescope. These large radio lobes have been argued to remain elusive at z > 4 due to energy losses in the synchrotron emitting plasma as a result of scattering of the strong cosmic microwave background at these high redshifts. Nonetheless, the 0 3 resolution radio image of J1601+3102 reveals a northern and a southern radio lobe located at 9 and 57 kpc from the optical quasar, respectively. The measured jet size of 66 kpc makes J1601+3102 the largest extended radio jet at z > 4 to date. However, it is expected to have an even larger physical size in reality due to projection effects brought about by the viewing angle. Furthermore, we observe the rest-frame UV spectrum of J1601+3102 with Gemini/GNIRS to examine its black hole properties, which results in a mass of 4.5 × 108M⊙ with an Eddington luminosity ratio of 0.45. The black hole mass is relatively low compared to the known high-z quasar population, which suggests that a high black hole mass is not strictly necessary to generate a powerful jet. This discovery of the first ∼100 kpc radio jet at z > 4 shows that these objects exist despite energy losses from inverse Compton scattering and can put invaluable constraints on the formation of the first radio-loud sources in the early Universe.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143192585","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 : 2025-02-06DOI: 10.3847/2041-8213/adad5e
A. Kashlinsky, Richard G. Arendt, M. L. N. Ashby, J. Kruk and N. Odegard
We use Spitzer/IRAC deep-exposure data covering two significantly larger than before sky areas to construct maps suitable for evaluating source-subtracted fluctuations in the cosmic infrared background (CIB). The maps are constructed using the self-calibration methodology eliminating artifacts to sufficient accuracy, and subset maps are selected in each area containing approximately uniform exposures. These maps are clipped and removed of known sources and then Fourier transformed to probe the CIB anisotropies to new larger scales. The power spectrum of the resultant CIB anisotropies is measured from the data to >1°, revealing the component well above that from remaining known galaxies on scales . The fluctuations are demonstrated to be free of Galactic and solar system foreground contributions out to the largest scales measured. We discuss the proposed theories for the origin of the excess CIB anisotropies in light of the new data. Out of these, the model where the CIB fluctuation excess originates from the granulation power due to LIGO-observed primordial black holes as dark matter appears most successful in accounting for all observations related to the measured CIB power amplitude and spatial structure, including the measured coherence between the CIB and unresolved cosmic X-ray background (CXB). Finally we point out the use of the data to probe the CIB-CXB cross power to new scales and higher accuracy. We also discuss the synergy of these data with future CIB programs at shorter near-IR wavelengths with deep wide surveys and subarcsecond angular resolution as provided by Euclid and Roman space missions.
{"title":"Looking at Infrared Background Radiation Anisotropies with Spitzer: Large-scale Anisotropies and Their Implications","authors":"A. Kashlinsky, Richard G. Arendt, M. L. N. Ashby, J. Kruk and N. Odegard","doi":"10.3847/2041-8213/adad5e","DOIUrl":"https://doi.org/10.3847/2041-8213/adad5e","url":null,"abstract":"We use Spitzer/IRAC deep-exposure data covering two significantly larger than before sky areas to construct maps suitable for evaluating source-subtracted fluctuations in the cosmic infrared background (CIB). The maps are constructed using the self-calibration methodology eliminating artifacts to sufficient accuracy, and subset maps are selected in each area containing approximately uniform exposures. These maps are clipped and removed of known sources and then Fourier transformed to probe the CIB anisotropies to new larger scales. The power spectrum of the resultant CIB anisotropies is measured from the data to >1°, revealing the component well above that from remaining known galaxies on scales . The fluctuations are demonstrated to be free of Galactic and solar system foreground contributions out to the largest scales measured. We discuss the proposed theories for the origin of the excess CIB anisotropies in light of the new data. Out of these, the model where the CIB fluctuation excess originates from the granulation power due to LIGO-observed primordial black holes as dark matter appears most successful in accounting for all observations related to the measured CIB power amplitude and spatial structure, including the measured coherence between the CIB and unresolved cosmic X-ray background (CXB). Finally we point out the use of the data to probe the CIB-CXB cross power to new scales and higher accuracy. We also discuss the synergy of these data with future CIB programs at shorter near-IR wavelengths with deep wide surveys and subarcsecond angular resolution as provided by Euclid and Roman space missions.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"10 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143258003","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 : 2025-02-06DOI: 10.3847/2041-8213/adad65
Weiming Xu, Can Liu, Ao Zhang, Maggie Lau, H. James Cleaves, Fang Huang, Christopher R. Glein and Jihua Hao
The Cassini spacecraft revealed life-forming elements like CHNOP and diverse organic compounds from Enceladus’s ocean. However, the availability of minor but bio-essential nutrients such as iron and sulfur remains unknown. Here, we perform geochemical modeling to explore their chemistry in Enceladus’s ocean. We find that dissolved iron predominantly occurs as Fe(ii) with a solubility ranging from 10−8 to 10−5 mole (kg H2O)−1 (decreasing with increasing pH). Dissolved sulfur, mainly present as HS−, is predicted to have a concentration of 10−6 to 10−4 mole (kg H2O)−1, and pH has only a minor effect on S solubility. Our predicted availabilities of Fe and S are close to measured concentrations in inhabited terrestrial serpentinization fluids, implying sufficient nutrients to support potential life. Our results also suggest that the reduction of ferric iron or sulfate might supply enough energy for chemotrophic metabolisms based on these reactions to complement previously proposed methanogenesis. The levels of bioproductivity supported by S availability are overall lower than those sustained by other nutrients, but still orders of magnitude higher than the maximum level of bioproductivity estimated from the supply of chemical energy.
{"title":"Enough Sulfur and Iron for Potential Life Make Enceladus’s Ocean Fully Habitable","authors":"Weiming Xu, Can Liu, Ao Zhang, Maggie Lau, H. James Cleaves, Fang Huang, Christopher R. Glein and Jihua Hao","doi":"10.3847/2041-8213/adad65","DOIUrl":"https://doi.org/10.3847/2041-8213/adad65","url":null,"abstract":"The Cassini spacecraft revealed life-forming elements like CHNOP and diverse organic compounds from Enceladus’s ocean. However, the availability of minor but bio-essential nutrients such as iron and sulfur remains unknown. Here, we perform geochemical modeling to explore their chemistry in Enceladus’s ocean. We find that dissolved iron predominantly occurs as Fe(ii) with a solubility ranging from 10−8 to 10−5 mole (kg H2O)−1 (decreasing with increasing pH). Dissolved sulfur, mainly present as HS−, is predicted to have a concentration of 10−6 to 10−4 mole (kg H2O)−1, and pH has only a minor effect on S solubility. Our predicted availabilities of Fe and S are close to measured concentrations in inhabited terrestrial serpentinization fluids, implying sufficient nutrients to support potential life. Our results also suggest that the reduction of ferric iron or sulfate might supply enough energy for chemotrophic metabolisms based on these reactions to complement previously proposed methanogenesis. The levels of bioproductivity supported by S availability are overall lower than those sustained by other nutrients, but still orders of magnitude higher than the maximum level of bioproductivity estimated from the supply of chemical energy.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"55 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143258004","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 : 2025-02-06DOI: 10.3847/2041-8213/adade9
Maureen Cohen, James Holmes, Stephen Lewis, Manish Patel and Sébastien Lebonnois
Because of its rotation period of 243 days, Venus is considered a slowly rotating planet. However, its persistent superrotating atmospheric jets, which increase in speed from surface to cloud tops, effectively set a faster rotation speed than the surface rotation. Using the Venus Planetary Climate Model and wind measurements taken by the Pioneer Venus entry probes, we show that the Rossby radius of deformation of the atmosphere varies with height. The atmosphere falls into three circulation regimes: (1) from the surface to 20 km, the Rossby radius of deformation exceeds the planetary radius and no Rossby waves form; (2) from 20 to 50 km, the tropical Rossby radius becomes smaller than the planetary radius, and a circulation regime characterized by a superrotating equatorial jet and mid-latitude Rossby gyres appears; (3) from 50 to 70 km, the extratropical Rossby radius becomes smaller than the planetary radius, the jet develops mid-latitude maxima, and the Rossby gyres shift to high latitudes. Studies of exoplanetary circulation regimes as a function of rotation period have repeatedly shown a similar progression. While observing the circulations of exoplanets to confirm these predictions is not currently possible, the presence of different circulation regimes on Venus and their dependence on altitude could be tested by observing campaigns. Such evidence would be the first observational support for the theory connecting differences in planetary rotation periods to circulation regime transitions and would ground predictions of exoplanet circulations in a validated framework.
{"title":"Three Worlds in One: Venus as a Natural Laboratory for the Effect of Rotation Period on Atmospheric Circulation","authors":"Maureen Cohen, James Holmes, Stephen Lewis, Manish Patel and Sébastien Lebonnois","doi":"10.3847/2041-8213/adade9","DOIUrl":"https://doi.org/10.3847/2041-8213/adade9","url":null,"abstract":"Because of its rotation period of 243 days, Venus is considered a slowly rotating planet. However, its persistent superrotating atmospheric jets, which increase in speed from surface to cloud tops, effectively set a faster rotation speed than the surface rotation. Using the Venus Planetary Climate Model and wind measurements taken by the Pioneer Venus entry probes, we show that the Rossby radius of deformation of the atmosphere varies with height. The atmosphere falls into three circulation regimes: (1) from the surface to 20 km, the Rossby radius of deformation exceeds the planetary radius and no Rossby waves form; (2) from 20 to 50 km, the tropical Rossby radius becomes smaller than the planetary radius, and a circulation regime characterized by a superrotating equatorial jet and mid-latitude Rossby gyres appears; (3) from 50 to 70 km, the extratropical Rossby radius becomes smaller than the planetary radius, the jet develops mid-latitude maxima, and the Rossby gyres shift to high latitudes. Studies of exoplanetary circulation regimes as a function of rotation period have repeatedly shown a similar progression. While observing the circulations of exoplanets to confirm these predictions is not currently possible, the presence of different circulation regimes on Venus and their dependence on altitude could be tested by observing campaigns. Such evidence would be the first observational support for the theory connecting differences in planetary rotation periods to circulation regime transitions and would ground predictions of exoplanet circulations in a validated framework.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"79 2 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143257963","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 : 2025-02-05DOI: 10.3847/2041-8213/adad62
Ankan Sur, Roberto Tejada Arevalo, Yubo Su and Adam Burrows
With the recent realization that there likely are stably stratified regions in the interiors of both Jupiter and Saturn, we construct new nonadiabatic, inhomogeneous evolutionary models with the same microphysics for each that result at the present time in respectable fits for all major bulk observables for both planets. These include the effective temperature, radius, atmospheric heavy-element and helium abundances (including helium rain), and the lower-order gravity moments J2 and J4. The models preserve from birth most of an extended “fuzzy” heavy-element core. Our predicted atmospheric helium mass fraction for Saturn is ∼0.2, close to some measured estimates but in disagreement with some published predictions. To preserve a fuzzy core from birth, the interiors of both planets must start out at lower entropies than would be used for traditional “hot start” adiabatic models, though the initial exterior mantle entropies can range from hot to warm start values. We do not see a helium ocean in Saturn’s interior, and both models have inner envelopes with significant Brunt–Väisälä frequencies; this region for Saturn at the current epoch is more extended, and in it, the Brunt is larger. The total heavy-element mass fraction in Jupiter and in Saturn is determined to be ∼14% and ∼26%, respectively, though there is some play in these determinations.
{"title":"Simultaneous Evolutionary Fits for Jupiter and Saturn Incorporating Fuzzy Cores","authors":"Ankan Sur, Roberto Tejada Arevalo, Yubo Su and Adam Burrows","doi":"10.3847/2041-8213/adad62","DOIUrl":"https://doi.org/10.3847/2041-8213/adad62","url":null,"abstract":"With the recent realization that there likely are stably stratified regions in the interiors of both Jupiter and Saturn, we construct new nonadiabatic, inhomogeneous evolutionary models with the same microphysics for each that result at the present time in respectable fits for all major bulk observables for both planets. These include the effective temperature, radius, atmospheric heavy-element and helium abundances (including helium rain), and the lower-order gravity moments J2 and J4. The models preserve from birth most of an extended “fuzzy” heavy-element core. Our predicted atmospheric helium mass fraction for Saturn is ∼0.2, close to some measured estimates but in disagreement with some published predictions. To preserve a fuzzy core from birth, the interiors of both planets must start out at lower entropies than would be used for traditional “hot start” adiabatic models, though the initial exterior mantle entropies can range from hot to warm start values. We do not see a helium ocean in Saturn’s interior, and both models have inner envelopes with significant Brunt–Väisälä frequencies; this region for Saturn at the current epoch is more extended, and in it, the Brunt is larger. The total heavy-element mass fraction in Jupiter and in Saturn is determined to be ∼14% and ∼26%, respectively, though there is some play in these determinations.","PeriodicalId":501814,"journal":{"name":"The Astrophysical Journal Letters","volume":"9 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143192587","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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