bluuebunny/crossref_metadata_2025_split huggingface dataset:
Linearized Field Deblending: Point-spread Function Photometry for Impatient Astronomers
Authors: Hedges Christina , Luger Rodrigo , Martinez-Palomera Jorge , Dotson Jessie , Barentsen Geert 
Published: August 2021

Abstract
NASA’s Kepler, K2, and TESS missions employ simple aperture photometry to derive time-series photometry, where an aperture is estimated for each star, and pixels containing each star are summed to create a single light curve. This method is simple, but in crowded fields, the derived time series can be highly contaminated. The alternate method of fitting a point-spread function (PSF) to the data is able to account for crowding but is computationally expensive. In this paper, we present a new approach to extracting photometry from these time-series missions that fits the PSF directly but makes simplifying assumptions in order to greatly reduce the computation expense. Our method fixes the scene of the field in each image, estimates the PSF shape of the instrument with a linear model, and allows only source flux and position to vary. We demonstrate that our method is able to separate the photometry from blended targets in the Kepler data set that are separated by less than a pixel. Our method is fast to compute and fully accounts for uncertainties from degeneracies due to crowded fields. We name the method described in this work linearized field deblending photometry. We demonstrate our method on the false-positive Kepler target KOI-608. We are able to separate the photometry of the two sources in the data and demonstrate that the contaminating transiting signal is consistent with a small, substellar companion with a radius of 2.67 R
Jup (0.27 R
☉). Our method is equally applicable to extracting photometry from NASA’s TESS mission.
The Sun’s Magnetic (Hale) Cycle and 27 Day Recurrences in the aa Geomagnetic Index
Authors: Chapman S. C. , McIntosh S. W. , Leamon R. J. , Watkins N. W. 
Published: August 2021

Abstract
We construct a new solar cycle phase clock which maps each of the last 18 solar cycles onto a single normalized epoch for the approximately 22 yr Hale (magnetic polarity) cycle, using the Hilbert transform of daily sunspot numbers (SSNs) since 1818. The occurrences of solar maxima show almost no discernible Hale cycle dependence, consistent with the clock being synchronized to polarity reversals. We reengineer the Sargent R27 index and combine it with our epoch analysis to obtain a high time resolution parameter for 27 day recurrence in aa, 〈acv(27)〉. This reveals that the transition to recurrence, that is, to an ordered solar wind dominated by high-speed streams, is fast, with an upper bound of a few solar rotations. It resolves an extended late declining phase which is approximately twice as long on even Schwabe cycles as odd. Galactic cosmic ray flux rises in step with 〈acv(27)〉 but then stays high. Our analysis also identifies a slow-timescale trend in SSN that simply tracks the Gleissberg cycle. We find that this trend is in phase with the slow-timescale trend in the modulus of sunspot latitudes, and in antiphase with that of the R27 index.
Radio Detection of PSR J1813–1749 in HESS J1813–178: The Most Scattered Pulsar Known
Authors: Camilo F. , Ransom S. M. , Halpern J. P. , Roshi D. Anish 
Published: August 2021

Abstract
The 44.7 ms X-ray pulsar in the supernova remnant G12.82−0.02/HESS J1813−178 has the second highest spin-down luminosity of known pulsars in the Galaxy, with

E

̇

=
5.6
×

10

37

erg s−1. Using the Green Bank Telescope, we have detected radio pulsations from PSR J1813−1749 at 4.4–10.2 GHz. The pulse is highly scattered, with an exponential decay timescale τ longer than that of any other pulsar at these frequencies. A point source detected at this position by Dzib et al. in several observations with the Jansky Very Large Array can be attributed to the pulsed emission. The steep dependence of τ on observing frequency explains why all previous pulsation searches at lower frequencies failed (τ ≈ 0.25 s at 2 GHz). The large dispersion measure, DM = 1087 pc cm−3, indicates a distance of either 6.2 or 12 kpc according to two widely used models of the electron density distribution in the Galaxy. These disfavor a previously suggested association with a young stellar cluster at the closer distance of 4.8 kpc. The high X-ray measured column density of ≈1023 cm−2 also supports a large distance. If d ≈ 12 kpc, HESS J1813−178 would be one of the most luminous TeV sources in the Galaxy.
An Improved and Physically Motivated Scheme for Matching Galaxies with Dark Matter Halos
Authors: Tonnesen Stephanie , Ostriker Jeremiah P. 
Published: August 2021

Abstract
The simplest scheme for predicting real galaxy properties after performing a dark matter simulation is to rank order the real systems by stellar mass and the simulated systems by halo mass and then simply assume monotonicity—that the more massive halos host the more massive galaxies. This has had some success, but we study here if a better motivated and more accurate matching scheme is easily constructed by looking carefully at how well one could predict the simulated IllustrisTNG galaxy sample from its dark matter computations. We find that using the dark matter rotation curve peak velocity, v
max, for normal galaxies reduces the error of the prediction by 30% (18% for central galaxies and 60% for satellite systems)—following expectations from the physics of monolithic collapse. For massive systems with halo mass >1012.5
M
⊙ hierarchical merger driven formation is the better model and dark matter halo mass remains the best single metric. Using a new single variable that combines these effects, ϕ = v
max/

v

max
,
12.7

+ M
peak/(1012.7
M
⊙) allows further improvement and reduces the error, as compared to ranking by dark matter mass at z = 0 by another 6% from v
max ranking. Two parameter fits—including environmental effects produce only minimal further impact.
The Blue Supergiant Progenitor of the Supernova Imposter AT 2019krl
Authors: Andrews Jennifer E. , Jencson Jacob E. , Van Dyk Schuyler D. , Smith Nathan , Neustadt Jack M. M. , Sand David J. , Kreckel K. , Kochanek C. S. , Valenti S. , Strader Jay , Bersten M. C. , Blanc Guillermo A. , Bostroem K. Azalee , Brink Thomas G. , Emsellem Eric , Filippenko Alexei V. , Folatelli Gastón , Kasliwal Mansi M. , Masci Frank J. , McElroy Rebecca , Milisavljevic Dan , Santoro Francesco , Szalai Tamás 
Published: August 2021

Abstract
Extensive archival Hubble Space Telescope, Spitzer Space Telescope, and Large Binocular Telescope imaging of the recent intermediate-luminosity transient, AT 2019krl in M74, reveal a bright optical and mid-infrared progenitor star. While the optical peak of the event was missed, a peak was detected in the infrared with an absolute magnitude of M
4.5 μm = −18.4 mag, leading us to infer a visual-wavelength peak absolute magnitude of −13.5 to −14.5. The pre-discovery light curve indicated no outbursts over the previous 16 yr. The colors, magnitudes, and inferred temperatures of the progenitor best match a 13–14 M
⊙ yellow or blue supergiant (BSG) if only foreground extinction is taken into account, or a hotter and more massive star if any additional local extinction is included. A pre-eruption spectrum of the star reveals strong Hα and [N ii] emission with wings extending to ±2000 km s−1. The post-eruption spectrum is fairly flat and featureless with only Hα, Na i D, [Ca ii], and the Ca ii triplet in emission. As in many previous intermediate-luminosity transients, AT 2019krl shows remarkable observational similarities to luminous blue variable (LBV) giant eruptions, SN 2008S-like events, and massive-star mergers. However, the information about the pre-eruption star favors either a relatively unobscured BSG or a more extinguished LBV with M > 20 M⊙ likely viewed pole-on.
Characterization of HD 206893 B from Near- to Thermal-infrared
Authors: Meshkat Tiffany , Gao Peter , Lee Eve J. , Mawet Dimitri , Choquet Elodie , Ygouf Marie , Patel Rahul , Ruane Garreth , Wang Jason , Wallack Nicole , Absil Olivier , Beichman Charles 
Published: August 2021

Abstract
HD 206893 B is a brown-dwarf companion orbiting inside the debris disk of its host star. We detect the brown dwarf in the Ms band using the Keck/NIRC2 instrument and vortex coronagraph. We measure its magnitude to be

Ms
=

12.97

−
0.11

0.10

. It is at an angular separation of 0.″22 ± 0.″03, and a position angle of 39.6° ± 5.4° east of north. Using this Ms-band measurement and the system age, we use three evolutionary models to estimate the mass to be 12–78 M
Jup. We analyze the atmospheric properties from 1–5 μm using a grid of simulated atmospheric models. We find that a sedimentation flux f
sed value ∼0.2 provides the best fit to the data, suggesting high vertically extended clouds. This may be indicative of high-altitude grains or a circumplanetary disk. Our model radii and luminosities for the companion find the best fits are ages of <100 Myr and masses <20 M
Jup, consistent with our mass estimate from the evolutionary models using the Ms-band data alone. We detect orbital motion of the brown dwarf around the host star in comparison to the discovery image and derive orbital parameters. Finally we analyze how the companion brown dwarf interacts with the debris disk by estimating the location of the chaotic zone around the brown dwarf using values derived from this study’s estimated mass and orbital constraints. We find that the collisions within the debris belt are likely driven by secular perturbations from the brown dwarf, rather than self-stirring.
Evolution of High-redshift Quasar Hosts and Promotion of Massive Black Hole Seed Formation
Authors: Li 李 Wenxiu 文秀 , Inayoshi Kohei , Qiu 邱 Yu 宇 
Published: August 2021

Abstract
High-redshift luminous quasars powered by accreting supermassive black holes (SMBHs) with mass ≳109
M
⊙ constrain their formation pathways. We investigate the formation of heavy seeds of SMBHs through gas collapse in the quasar host progenitors, using merger trees to trace the halo growth in highly biased, overdense regions of the universe. The progenitor halos are likely irradiated by intense H2-photodissociating radiation from nearby star-forming galaxies and heat the interior gas by successive mergers. The kinetic energy of the gas originating from mergers, as well as the baryonic streaming motion, prevents gas collapse and delays prior star formation. With a streaming velocity higher than the rms value, gas clouds in nearly all 104 realizations of merger trees enter the atomic-cooling stage and begin to collapse isothermally with T ≃ 8000 K via Lyα cooling. The fraction of trees that host isothermal gas collapse is 14% and increases with streaming velocity, while the rest form H2-cooled cores after short isothermal phases. If the collapsing gas is enriched to Z
crit ∼ 2 × 10−3
Z
⊙, requiring efficient metal mixing, this fraction could be reduced by additional cooling via metal fine-structure lines. In the massive collapsing gas, the accretion rate onto a newly born protostar ranges between 3 × 10−3
M
⊙ yr−1 and 5 M
⊙ yr−1, among which a large fraction exceeds the critical rate suppressing stellar radiative feedback. As a result, we expect a distribution of stellar mass (presumably BH mass) ranging from several hundred to above 105
M
⊙, potentially forming massive BH binary mergers and yielding gravitational-wave events.
Iron and Nickel Isotopes in IID and IVB Iron Meteorites: Evidence for Admixture of an SN II Component and Implications for the Initial Abundance of 60Fe
Authors: Cook David L. , Meyer Bradley S. , Schönbächler Maria 
Published: August 2021

Abstract
We measured Fe and Ni isotopes in 13 iron meteorites from magmatic groups IID and IVB. Resolvable deficits (≈−0.14) are observed in ε
60Ni in both groups. Small deficits (≈−0.08) are also evident in ε
56Fe but not in the most neutron-rich isotope of Fe (58Fe). Relative to terrestrial material, the observed ε
iFe values are consistent with the presence of a small excesses of material in the parent bodies of IID and IVB irons that was produced in a type II supernova. The ε
60Ni and ε
56Fe values are uncorrelated in both groups. This is consistent with a nucleosynthetic origin of the ε
56Fe deficits, whereas the ε
60Ni deficits are best explained as radiogenic in nature due to the former presence of live 60Fe (t
1/2 = 2.62 Ma) in the early solar system. The 60Ni deficits correspond to 60Fe/56Fe ratios of ≈3 × 10−7 at the time of core formation on the IID and IVB parent bodies. These data, in conjunction with previously published 182Hf–182W core formation ages, are used to estimate a solar system initial 60Fe/56Fe = (6.4 ± 2.0) × 10−7 for the formation region of carbonaceous chondrites.
Future Constraints on the Reionization History and the Ionizing Sources from Gamma-Ray Burst Afterglows
Authors: Lidz Adam , Chang Tzu-Ching , Mas-Ribas Lluís , Sun Guochao 
Published: August 2021

Abstract
We forecast the reionization history constraints, inferred from Lyα damping wing absorption features, for a future sample of ∼20 z ≥ 6 gamma-ray burst (GRB) afterglows. We describe each afterglow spectrum by a three-parameter model. First, L characterizes the size of the ionized region (the “bubble size”) around a GRB host halo. Second, 〈x
H i
〉 is the volume-averaged neutral fraction outside of the ionized bubble around the GRB, which is approximated as spatially uniform. Finally, N
H i
denotes the column density of a local damped Lyα absorber (DLA) associated with the GRB host galaxy. The size distribution of ionized regions is extracted from a numerical simulation of reionization and evolves strongly across the epoch of reionization (EoR). The model DLA column densities follow the empirical distribution determined from current GRB afterglow spectra. We use a Fisher matrix formalism to forecast the 〈x
H i
(z)〉 constraints that can be obtained from follow-up spectroscopy of afterglows with S/N = 20 per R = 3000 resolution element at the continuum. We find that the neutral fraction may be determined to better than 10%–15% (1σ) accuracy from this data across multiple independent redshift bins at z ∼ 6–10, spanning much of the EoR, although the precision degrades somewhat near the end of reionization. A more futuristic survey with 80 GRB afterglows at z ≥ 6 can improve the precision here by a factor of 2 and extend measurements out to z ∼ 14. We further discuss how these constraints may be combined with estimates of the escape fraction of ionizing photons derived from the DLA column density distribution toward GRBs extracted at slightly lower redshift, z ∼ 5. This combination will help in testing whether we have an accurate census of the sources that reionized the universe.
Back to Quiescence: Postoutburst Evolution of the Pulsar J1119–6127 and Its Wind Nebula
Authors: Blumer Harsha , Safi-Harb Samar , Borghese Alice , Martín Jonatan , McLaughlin Maura A. , Torres Diego F. , Younes George 
Published: August 2021

Abstract
We report on the analysis of a deep Chandra observation of the high-magnetic-field pulsar (PSR) J1119–6127 and its compact pulsar wind nebula (PWN) taken in 2019 October, three years after the source went into outburst. The 0.5–7 keV postoutburst (2019) spectrum of the pulsar is best described by a two-component blackbody plus power-law model with a temperature of 0.2 ± 0.1 keV, photon index Γ = 1.8 ± 0.4, and X-ray luminosity of

1.9

−
0.3

+
0.3

×

1033 erg s−1, consistent with its preburst quiescent phase. We find that the pulsar has gone back to quiescence. The compact nebula shows a jet-like morphology elongated in the north–south direction, similar to the preburst phase. The postoutburst PWN spectrum is best fit by an absorbed power law with a photon index Γ = 2.3 ± 0.5 and a flux of

3.2

−
0.2

+
0.3

×10−14 erg cm−2 s−1 (0.5–7 keV). The PWN spectrum shows evidence of spectral softening in the postoutburst phase, with the preburst photon index Γ = 1.2 ± 0.4 changing to Γ = 2.3 ± 0.5 and the preburst luminosity of

1.5

−
0.2

+
0.3

× 1032 erg s−1 changing to

2.7

−
0.2

+
0.3

× 1032 erg s−1 in the 0.5–7 keV band, suggesting magnetar outbursts can impact PWNe. The observed timescale for returning to quiescence, of just a few years, implies a rather fast cooling process and favors a scenario where J1119 is temporarily powered by magnetic energy following the magnetar outburst, in addition to its spin-down energy.
Registres de pensée et sphères d’activité des doctorants en situation de confinement
Authors: Saboya Fabienne , Jorro Anne 
Published: August 2021

Notre recherche tente de comprendre les effets du premier confinement sur les doctorants de SHS du Cnam de Paris. Hybridation des cours puis passage au distanciel ont profondément transformé leur expérience de la formation doctorale en les éloignant de leur communauté de pratique. Les approches sociologiques de la construction de significations et de modes d’action dans une situation d’épreuve (Boltanski, 2009 ; Heinich, 2017), les théorisations de l’activité (Clot, 2000) ont été mobilisées pour comprendre la spécificité de cette expérience inédite du confinement. L’analyse de dix entretiens semi-directifs, menés auprès de doctorants confrontés aux différents types d’épreuves générées par la crise sanitaire, met en évidence des transformations dans leurs manières de penser, de ressentir et d’agir.
Créativité intégrée des pratiques évaluatives : entre routines et opportunités
Authors: Mercier-Brunel Yann , Crocé-Spinelli Hélène 
Published: August 2021

En France, l’activité évaluative des enseignants reste dominée par la mesure de performances (Vial, 2012) et un jugement normatif (Jorro et Mercier-Brunel, 2014), maintenant le caractère stressant et socialement discriminant de l’évaluation (Pisa, 2018). Notre article étudie le déploiement d’une « créativité de l’agir » (Joas, 1999) féconde à partir de certaines routines. En nous appuyant sur une recherche collaborative menée entre 2017 et 2019, impliquant neuf chercheurs et vingt-six enseignants dans un Réseau d’éducation prioritaire proche de Lyon, nous analysons comment deux enseignants développent des pratiques évaluatives créatives à partir d’une situation de tension et de ressources disponibles.
Frequency-Doubled Nd:YAG Laser Treatment for Premacular Hemorrhage
Authors: Puthalath Suresh , Chirayath Anup , Shermila M. V. , Sunil M. S. , Ramakrishnan R. 
Published: August 2021

BACKGROUND AND OBJECTIVE:
Premacular hemorrhage occurs as a result of Valsalva retinopathy, proliferative diabetic retinopathy, and retinal artery macroaneurysm and may cause sudden, profound visual loss. Currently, it is managed with observation or vitrectomy. An alternative method of treatment is by Nd:YAG laser or argon laser membranotomy. This study investigates the efficacy of frequency-doubled Nd:YAG laser membranotomy.

PATIENTS AND METHODS:
Twelve patients had frequency-doubled Nd:YAG laser membranotomy as a two-step procedure to drain premacular hemorrhage: two stretch burns to make the membrane stable and taut and then placement of penetration burns between stretch burns. The follow-up period was 18 months.

RESULTS:
Ten eyes had marked clearing of hemorrhage and immediate improvement of vision following the laser treatment. One eye with retinal macro-aneurysm and another with proliferative diabetic retinopathy did not show marked improvement immediately following membranotomy.

CONCLUSION:
Frequency-doubled Nd:YAG membranotomy is a safe, simple, and noninvasive alternative to conservative treatment or vitrectomy and allows faster resolution of premacular hemorrhage.

[Ophthalmic Surg Lasers Imaging 2003;34:284–290.]
Racket or Bat Sports: No Association With Thumb-Base Osteoarthritis
Authors: Driban Jeffrey B. , Lo Grace H. , Roberts Mary B. , Harkey Matthew S. , Schaefer Lena F. , Haugen Ida K. , Smith Stacy E. , Duryea Jeffrey , Lu Bing , Eaton Charles B. , Hochberg Marc C. , Jackson Rebecca D. , Kwoh C. Kent , Nevitt Michael C. , McAlindon Timothy E. 
Published: August 2021

Context
Repetitive joint use is a risk factor for osteoarthritis, which is a leading cause of disability. Sports requiring a racket or bat to perform repetitive high-velocity impacts may increase the risk of thumb-base osteoarthritis. However, this hypothesis remains untested.

Objective
To determine if a history of participation in racket or bat sports was associated with the prevalence of thumb-base osteoarthritis.

Design
Descriptive epidemiologic study.

Setting
Four US clinical sites associated with the Osteoarthritis Initiative.

Patients or Other Participants
We recruited 2309 men and women from the community. Eligible participants had dominant-hand radiographic readings, hand symptom assessments, and historical physical activity survey data.

Main Outcome Measure(s)
A history of exposure to racket or bat sports (badminton, baseball or softball, racketball or squash, table tennis [or ping pong], tennis [doubles], or tennis [singles]) was based on self-reported recall data covering 3 age ranges (12–18, 19–34, and 35–49 years). Prevalent radiographic thumb-base osteoarthritis was defined as Kellgren-Lawrence grade &gt;2 in the first carpometacarpal joint or scaphotrapezoidal joint at the Osteoarthritis Initiative baseline visit. Symptomatic thumb-base osteoarthritis was defined as radiographic osteoarthritis and hand or finger symptoms.

Results
Radiographic or symptomatic thumb-base osteoarthritis was present in 355 (34%) and 56 (5%), respectively, of men (total = 1049) and 535 (42%) and 170 (13%), respectively, of women (total = 1260). After adjusting for age, race, and education level, we found no significant associations between a history of any racket or bat sport participation and thumb-base osteoarthritis (radiographic or symptomatic; odds ratios ranged from 0.82 to 1.34).

Conclusions
In a community-based cohort, a self-reported history of participation in racket or bat sports was not associated with increased odds of having radiographic or symptomatic thumb-base osteoarthritis in the dominant hand.
Automated Landing Error Scoring System Performance and the Risk of Bone Stress Injury in Military Trainees
Authors: Eckard Timothy G. , Miraldi Story F.P. , Peck Karen Y. , Posner Matthew A. , Svoboda Steven J. , DiStefano Lindsay J. , Padua Darin A. , Marshall Stephen W. , Cameron Kenneth L. 
Published: August 2021

ContextLower extremity bone stress injuries (BSIs) place a significant burden on the health and readiness of the US Armed Forces.ObjectiveTo determine if preinjury baseline performance on an expanded and automated 22-item version of the Landing Error Scoring System (LESS-22) was associated with the incidence of BSIs in a military training population.DesignProspective cohort study.SettingUS Military Academy at West Point, NY.Patients or Other ParticipantsA total of 2235 incoming cadets (510 females [22.8%]).Main Outcome Measure(s)Multivariable Poisson regression models were used to produce adjusted incidence rate ratios (IRRs) to quantify the association between preinjury LESS scores and BSI incidence rate during follow-up and were adjusted for pertinent risk factors. Risk factors were included as covariates in the final model if the 95% CI for the crude IRR did not contain 1.00.ResultsA total of 54 BSIs occurred during the study period, resulting in an overall incidence rate of 0.07 BSI per 1000 person-days (95% CI = 0.05, 0.09). The mean number of exposure days was 345.4 ± 61.12 (range = 3–368 days). The final model was adjusted for sex and body mass index and yielded an adjusted IRR for a LESS-22 score of 1.06 (95% CI = 1.002, 1.13; P = .04), indicating that each additional LESS error documented at baseline was associated with a 6.0% increase in the incidence rate of BSI during the follow-up period. In addition, 6 individual LESS-22 items, including 2 newly added items, were significantly associated with the BSI incidence.ConclusionsWe provided evidence that performance on the expanded and automated version of the LESS was associated with the BSI incidence in a military training population. The automated LESS-22 may be a scalable solution for screening military training populations for BSI risk.