The Astrophysical Journal Supplement Series最新文献

{"title":"SMA 200–400 GHz Survey for Dust Properties in the Icy Class II Disks in the Taurus Molecular Cloud","authors":"Chia-Ying Chung, Sean M. Andrews, Mark A. Gurwell, Melvyn Wright, Feng Long, Wenrui Xu, Hauyu Baobab Liu","doi":"10.3847/1538-4365/ad528b","DOIUrl":"https://doi.org/10.3847/1538-4365/ad528b","url":null,"abstract":"We present a new Submillimeter Array survey of 47 Class II sources in the Taurus–Auriga region. Our observations made 12 independent samples of flux densities over the 200–400 GHz frequency range. We tightly constrained the spectral indices of most sources to a narrow range of 2.0 ± 0.2; only a handful of spatially resolved (e.g., diameter &gt;250 au) disks present larger spectral indices. The simplest interpretation for this result is that the (sub)millimeter luminosities of all of the observed target sources are dominated by very optically thick (e.g., <italic toggle=\"yes\">τ</italic> ≳ 5) dust thermal emission. Some previous works that were based on the optically thin assumption thus might have underestimated optical depths by at least 1 order of magnitude. Assuming DSHARP dust opacities, this corresponds to underestimates of dust masses by a similar factor. For our specific selected sample, the lower limits of dust masses implied by the optically thick interpretation are 1–3 times higher than those previous estimates that were made based on the optically thin assumption. Moreover, some population synthesis models show that, to explain the observed, narrowly distributed spectral indices, the disks in our selected sample need to have very similar dust temperatures (<italic toggle=\"yes\">T</italic>\u0000_dust). Given a specific assumption of median <italic toggle=\"yes\">T</italic>\u0000_dust, the maximum grain sizes (<inline-formula>\u0000<tex-math>\u0000<?CDATA ${a}_{{rm{max }}}$?>\u0000</tex-math>\u0000<mml:math overflow=\"scroll\"><mml:msub><mml:mrow><mml:mi>a</mml:mi></mml:mrow><mml:mrow><mml:mi mathvariant=\"normal\">max</mml:mi></mml:mrow></mml:msub></mml:math>\u0000<inline-graphic xlink:href=\"apjsad528bieqn1.gif\" xlink:type=\"simple\"></inline-graphic>\u0000</inline-formula>) can also be constrained, which is a few times smaller than 0.1 mm for <italic toggle=\"yes\">T</italic>\u0000_dust ∼ 100 K and a few millimeters for <italic toggle=\"yes\">T</italic>\u0000_dust ∼ 24 K. The results may indicate that dust grain growth outside the water snow line is limited by the bouncing/fragmentation barriers. This is consistent with the recent laboratory experiments, which indicated that the coagulation of water-ice-coated dust is not efficient, and the water-ice-free dust is stickier and thus can coagulate more efficiently. In the Class II disks, the dust mass budget outside of the water snow line may be largely retained instead of being mostly consumed by planet formation. While Class II disks still possess sufficient dust masses to feed planet formation at a later time, it is unknown whether or not dust coagulation and planet formation can be efficient or natural outside of the water snow line.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"49 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141865417","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}

{"title":"LADDER: Revisiting the Cosmic Distance Ladder with Deep Learning Approaches and Exploring Its Applications","authors":"Rahul Shah, Soumadeep Saha, Purba Mukherjee, Utpal Garain and Supratik Pal","doi":"10.3847/1538-4365/ad5558","DOIUrl":"https://doi.org/10.3847/1538-4365/ad5558","url":null,"abstract":"We investigate the prospect of reconstructing the “cosmic distance ladder” of the Universe using a novel deep learning framework called LADDER—Learning Algorithm for Deep Distance Estimation and Reconstruction. LADDER is trained on the apparent magnitude data from the Pantheon Type Ia supernova compilation, incorporating the full covariance information among data points, to produce predictions along with corresponding errors. After employing several validation tests with a number of deep learning models, we pick LADDER as the best-performing one. We then demonstrate applications of our method in the cosmological context, including serving as a model-independent tool for consistency checks for other data sets like baryon acoustic oscillations, calibration of high-redshift data sets such as gamma-ray bursts, and use as a model-independent mock-catalog generator for future probes. Our analysis advocates for careful consideration of machine learning techniques applied to cosmological contexts.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"68 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141782175","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}

{"title":"Improving Cosmological Constraints by Inferring the Formation Channel of Extreme-mass-ratio Inspirals","authors":"Liang-Gui Zhu, 良贵 朱, Hui-Min Fan, 会敏 范, Xian Chen, 弦 陈, Yi-Ming Hu, 一鸣 胡, Jian-dong Zhang and 建东 张","doi":"10.3847/1538-4365/ad5446","DOIUrl":"https://doi.org/10.3847/1538-4365/ad5446","url":null,"abstract":"Extreme-mass-ratio inspirals (EMRIs) could be detected by space-borne gravitational-wave (GW) detectors, such as the Laser Interferometer Space Antenna (LISA), TianQin, and Taiji. Localizing EMRIs by GW detectors can help us select candidate host galaxies, which can be used to infer the cosmic expansion history. In this paper, we demonstrate that the localization information can also be used to infer the formation channel of EMRIs, and can hence allow us to extract more precisely the redshift probability distributions. By conducting mock observations of the EMRIs that can be detected by TianQin and LISA, as well as the galaxies that can be provided by the future Chinese Space Station Telescope, we find that TianQin can constrain the Hubble–Lemaître constant H0 to a precision of ∼3%–8% and the dark energy equation-of-state parameter w0 to ∼10%–40%. The TianQin+LISA network, by increasing the localization accuracy, can improve the precisions of H0 and w0 to ∼0.4%–7% and ∼4%–20%, respectively. Then, considering an illustrative case in which all EMRIs originate in active galactic nuclei (AGNs), and combining the mock EMRI observation with a mock AGN catalog, we show that TianQin can recognize the EMRI–AGN correlation with ∼1300 detections. The TianQin+LISA network can reduce this required number to ∼30. Additionally, we propose a statistical method to directly estimate the fraction of EMRIs produced in AGNs, fagn, and show that observationally deriving this value could significantly improve the constraints on the cosmological parameters. These results demonstrate the potentials of using EMRIs as well as galaxy and AGN surveys to improve the constraints on cosmological parameters and the formation channel of EMRIs.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"40 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141782178","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}

{"title":"Observations of Five Major Uranian Satellites during 2013–2020 Based on Gaia DR3","authors":"H. Y. Zhang, Y. Yu, R. C. Qiao, D. Yan, X. Cheng, K. Tang and Y. D. Mao","doi":"10.3847/1538-4365/ad53c4","DOIUrl":"https://doi.org/10.3847/1538-4365/ad53c4","url":null,"abstract":"A total of 10,339 positions of the five major Uranian satellites (Ariel, Umbriel, Titania, Oberon and Miranda) were collected at the Yunnan Observatories from 2013 to 2020 with the 1.0 m astrometric reflector. A median filtering method was applied to reduce the influence of the bright Uranus halo. All CCD observational data was analyzed by the newly developed CCD image-processing software with Gaia DR3 as the reference catalog. The impact of different exposure times on satellite positioning accuracy was evaluated. The observational positions of satellites were compared with theoretical positions from Institut de Mécanique Céleste et de Calcul des Éphémérides (DE441 and Lainey et al. 2015) and the mean offsets are from −0.″115 to 0.″103 in both R.A. and decl. for the five satellites. The standard deviation of the offsets are from 0.″008 to 0.″086 for the four greatest Uranian satellites and from 0.″037 to 0.″132 for Miranda in each direction. These precise observations of the five major Uranian satellites over an 8 yr period will be very useful for improving the orbital parameters of both Uranus and its five major satellites.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"42 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141782177","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}

{"title":"Cosmology Large Angular Scale Surveyor (CLASS): 90 GHz Telescope Pointing, Beam Profile, Window Function, and Polarization Performance","authors":"Rahul Datta, Michael K. Brewer, Jullianna Denes Couto, Joseph Eimer, Yunyang Li, 云炀 李, Zhilei Xu, 智磊 徐, Aamir Ali, John W. Appel, Charles L. Bennett, Ricardo Bustos, David T. Chuss, Joseph Cleary, Sumit Dahal, Francisco Raul Javier Espinoza Inostroza, Thomas Essinger-Hileman, Pedro Fluxá, Kathleen Harrington, Kyle Helson, Jeffrey Iuliano, John Karakla, Tobias A. Marriage, Sasha Novack, Carolina Núñez, Ivan L. Padilla, Lucas Parker, Matthew A. Petroff, Rodrigo Reeves, Karwan Rostem, Rui Shi, 瑞 时, Deniz A. N. Valle, Duncan J. Watts, Janet L. Weiland, Edward J. Wollack and Lingzhen Zeng","doi":"10.3847/1538-4365/ad50a0","DOIUrl":"https://doi.org/10.3847/1538-4365/ad50a0","url":null,"abstract":"The Cosmology Large Angular Scale Surveyor (CLASS) is a telescope array that observes the cosmic microwave background (CMB) over ∼75% of the sky from the Atacama Desert, Chile, at frequency bands centered near 40, 90, 150, and 220 GHz. CLASS measures the large angular scale CMB polarization to constrain the tensor-to-scalar ratio and the optical depth to last scattering. This paper presents the optical characterization of the 90 GHz telescope. Observations of the Moon establish the pointing while dedicated observations of Jupiter are used for beam calibration. The standard deviations of the pointing error in azimuth, elevation, and boresight angle are 1.′3, 2.′1, and 2.′0, respectively, over the first 3 yr of observations. This corresponds to a pointing uncertainty ∼7% of the beam’s full width at half-maximum (FWHM). The effective azimuthally symmetrized instrument 1D beam estimated at 90 GHz has an FWHM of 0.°620 ± 0.°003 and a solid angle of 138.7 ± 0.6(stats.) ± 1.1(sys.) μsr integrated to a radius of 4°. The corresponding beam window function drops to at ℓ = 30, 100, 300, respectively. Far-sidelobes are studied using detector-centered intensity maps of the Moon and measured to be at a level of 10−3 or below relative to the peak. The polarization angle of Tau A estimated from preliminary survey maps is 149°.6 ± 0°.2(stats.) in equatorial coordinates. The instrumental temperature-to-polarization (T → P) leakage fraction, inferred from per-detector demodulated Jupiter scan data, has a monopole component at the level of 1.7 × 10−3, a dipole component with an amplitude of 4.3 × 10−3, with no evidence of quadrupolar leakage.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"38 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141782176","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}

{"title":"Pulsar Timing Arrays Require Hierarchical Models","authors":"Rutger van Haasteren","doi":"10.3847/1538-4365/ad530f","DOIUrl":"https://doi.org/10.3847/1538-4365/ad530f","url":null,"abstract":"Pulsar timing array (PTA) projects have found evidence of a stochastic background of gravitational waves (GWB) using data from an ensemble of pulsars. In the literature, minimal assumptions are made about the signal and noise processes that affect data from these pulsars, such as pulsar spin noise. These assumptions are encoded as uninformative priors in Bayesian searches, though frequentist approaches make similar assumptions. Uninformative priors are not suitable for (noise) properties of pulsars in an ensemble, and they bias estimates of model parameters such as gravitational-wave signal parameters. Both frequentist and Bayesian searches are affected. In this article, more appropriate priors are proposed in the language of hierarchical Bayesian modeling, where the properties of the ensemble of pulsars are jointly described with the properties of the individual components of the ensemble. Results by PTA projects should be reevaluated using hierarchical models.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"63 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141782180","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}

{"title":"The Plane Quasar Survey: First Data Release","authors":"Jessica Werk, Kirill Tchernyshyov, Hannah Bish, Yong Zheng, Mary Putman, Joshua Peek and David Schiminovich","doi":"10.3847/1538-4365/ad58df","DOIUrl":"https://doi.org/10.3847/1538-4365/ad58df","url":null,"abstract":"We present a sample of 305 QSO candidates having ∣b∣ < 30°, the majority with GALEX magnitudes near-UV < 18.75. To generate this sample, we apply UV–IR color selection criteria to photometric data from the Ultraviolet Galactic Plane Survey as part of GALEX-CAUSE, the Million Quasars Catalog, Gaia DR2, and Pan-STARRS DR1. 165 of these 305 candidate UV-bright active galactic nuclei (AGN; 54%) have published spectroscopic redshifts from 45 different surveys, confirming them as AGN. We further obtained low-dispersion, optical, long-slit spectra with the Apache Point Observatory 3.5 m, MDM 2.4 m, and MDM 1.3 m telescopes for 84 of the candidates, and confirm 86% (N = 72) as AGN, generally with z < 0.6. Of these 72 confirmed AGN, 25 are newly discovered low-latitude QSOs without any previous spectroscopy. These sources fill a gap in the Galactic latitude coverage of the available samples of known UV-bright QSO background probes. Along with a description of the confirmed QSO properties, we provide the fully reduced, flux- and wavelength-calibrated spectra of 72 low-latitude QSOs through the Mikulski Archive for Space Telescopes. Future Hubble Space Telescope/Cosmic Origins Spectrograph spectroscopy of these low-Galactic-latitude QSOs has the potential to transform our view of the Milky Way and Local Group circumgalactic medium.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"1 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141785839","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}

{"title":"Subaru Suprime-Cam Wide-field BVI Stellar Photometry of the M33 Galaxy","authors":"Rima Stonkutė and Vladas Vansevičius","doi":"10.3847/1538-4365/ad566e","DOIUrl":"https://doi.org/10.3847/1538-4365/ad566e","url":null,"abstract":"We have surveyed the complete extent of the disk of M33—a gas-rich low-mass dwarf spiral galaxy in the Local Group. The B-, V-, and I-passband (the Johnson–Cousins system) CCD images (typical seeing ∼0.″8) were obtained with the Subaru Telescope equipped with the Suprime-Cam mosaic camera. The wide-field (∼1.°0 × 1.°5) catalog of 803,095 (15 ≤ V ≤ 25) starlike objects, measured using the point-spread function and aperture photometry techniques, is presented. We determined the distance modulus of M33 using the tip of the red giant branch (ITRGB = 20.64 ± 0.02) as a reference point of (m − M)0 = 24.63 ± 0.02stat ± 0.06syst (843 kpc). We found young (≲100 Myr) stellar populations residing up to the deprojected radius of ∼10 kpc. The scale length of the young main-sequence (MS) star surface-number density in the range of radial distances from 7 to 9 kpc is 0.53 ± 0.03 kpc. The youngest MS stars (≲15 Myr) reside up to the radius of ∼8 kpc. This distribution of stellar populations may suggest an outside-in scenario of recent star formation in the disk of M33.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"20 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141782181","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}

{"title":"The NuSTAR Serendipitous Survey: The 80 Month Catalog and Source Properties of the High-energy Emitting Active Galactic Nucleus and Quasar Population","authors":"Claire L. Greenwell, Lizelke Klindt, George B. Lansbury, David J. Rosario, David M. Alexander, James Aird, Daniel Stern, Karl Forster, Michael J. Koss, Franz E. Bauer, Claudio Ricci, John Tomsick, William N. Brandt, Thomas Connor, Peter G. Boorman, Adlyka Annuar, David R. Ballantyne, Chien-Ting Chen, Francesca Civano, Andrea Comastri, Victoria A. Fawcett, Francesca M. Fornasini, Poshak Gandhi, Fiona Harrison, Marianne Heida, Ryan Hickox, Elias S. Kammoun, Lauranne Lanz, Stefano Marchesi, Gaël Noirot, Encarni Romero-Colmenero, Ezequiel Treister, C. Megan Urry, Petri Väisänen and Brian van Soelen","doi":"10.3847/1538-4365/ad4a71","DOIUrl":"https://doi.org/10.3847/1538-4365/ad4a71","url":null,"abstract":"We present a catalog of hard X-ray serendipitous sources detected in the first 80 months of observations by the Nuclear Spectroscopic Telescope Array (NuSTAR). The NuSTAR serendipitous survey 80 month (NSS80) catalog has an unprecedented ∼62 Ms of effective exposure time over 894 unique fields (a factor of 3 increase over the 40 month catalog, NSS40), with an areal coverage of ∼36 deg2, larger than all NuSTAR extragalactic surveys. NSS80 provides 1274 hard X-ray sources in the 3−24 keV band (822 new detections compared to the previous NSS40). Approximately 76% of the NuSTAR sources have lower-energy (<10 keV) X-ray counterparts from Chandra, XMM-Newton, and Swift-XRT. We have undertaken an extensive campaign of ground-based spectroscopic follow-up to obtain new source redshifts and classifications for 427 sources. Combining these with existing archival spectroscopy provides redshifts for 550 NSS80 sources, of which 547 are classified. The sample is primarily composed of active galactic nuclei (AGNs), detected over a large range in redshift (z = 0.012–3.43), but also includes 58 spectroscopically confirmed Galactic sources. In addition, five AGN–galaxy pairs, one dual AGN system, one BL Lac candidate, and a hotspot of 4C 74.26 (radio quasar) have been identified. The median rest-frame 10−40 keV luminosity and redshift of NSS80 are 〈L10−40 keV〉 = 1.2 × 1044 erg s−1 and 〈z〉 = 0.56. We investigate the optical properties and construct composite optical spectra to search for subtle signatures not present in the individual spectra, finding an excess of redder BL AGNs compared to optical quasar surveys, predominantly due to the presence of the host galaxy and, at least in part, due to dust obscuration.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"45 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141782179","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}

{"title":"Determining Stellar Elemental Abundances from DESI Spectra with the Data-driven Payne","authors":"Meng Zhang, Maosheng Xiang, Yuan-Sen Ting, Jiahui Wang, Haining Li, Hu Zou, Jundan Nie, Lanya Mou, Tianmin Wu, Yaqian Wu and Jifeng Liu","doi":"10.3847/1538-4365/ad51dd","DOIUrl":"https://doi.org/10.3847/1538-4365/ad51dd","url":null,"abstract":"Stellar abundances for a large number of stars provide key information for the study of Galactic formation history. Large spectroscopic surveys such as the Dark Energy Spectroscopic Instrument (DESI) and LAMOST take median-to-low-resolution (R ≲ 5000) spectra in the full optical wavelength range for millions of stars. However, the line-blending effect in these spectra causes great challenges for elemental abundance determination. Here we employ DD-Payne, a data-driven method regularized by differential spectra from stellar physical models, to the DESI early data release spectra for stellar abundance determination. Our implementation delivers 15 labels, including effective temperature Teff, surface gravity , microturbulence velocity vmic, and the abundances for 12 individual elements, namely C, N, O, Mg, Al, Si, Ca, Ti, Cr, Mn, Fe, and Ni. Given a spectral signal-to-noise ratio of 100 per pixel, the internal precisions of the label estimates are about 20 K for Teff, 0.05 dex for , and 0.05 dex for most elemental abundances. These results agree with the theoretical limits from the Crámer–Rao bound calculation within a factor of 2. The majority of the accreted halo stars contributed by the Gaia–Enceladus–Sausage are discernible from the disk and in situ halo populations in the resultant [Mg/Fe]–[Fe/H] and [Al/Fe]–[Fe/H] abundance spaces. We also provide distance and orbital parameters for the sample stars, which spread over a distance out to ∼100 kpc. The DESI sample has a significantly higher fraction of distant (or metal-poor) stars than the other existing spectroscopic surveys, making it a powerful data set for studying the Galactic outskirts. The catalog is publicly available.","PeriodicalId":22368,"journal":{"name":"The Astrophysical Journal Supplement Series","volume":"92 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141719786","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}