bluuebunny/crossref_metadata_2025_split huggingface dataset:
Glitches in four gamma-ray pulsars and inferences on the neutron star structure
Authors: Gügercinoğlu E , Ge M Y , Yuan J P , Zhou S Q 
Published: January 2022

ABSTRACT
We present timing solutions from the Fermi-LAT observations of gamma-ray pulsars PSR J0835 − 4510 (Vela), PSR J1023−5746, PSR J2111+4606, and PSR J2229+6114. Data ranges for each pulsar extend over a decade. From data analysis, we have identified a total of 20 glitches, 11 of which are new discoveries. Among them, 15 glitches are large ones with Δν/ν ≳ 10−6. PSR J1023−5746 is the most active pulsar with glitch activity parameter being Ag = 14.5 × 10−7 yr−1 in the considered data span and should be a target for frequently glitching Vela-like pulsars in future observations. We have done fits within the framework of the vortex creep model for 16 glitches with Δν/ν ≳ 10−7. By theoretical analysis of these glitches, we are able to obtain important information on the structure of neutron star, including moments of inertia of the superfluid regions participated in glitches and coupling time-scales between various stellar components. The theoretical prediction for the time to the next glitch from the parameters of the previous one is found to be in qualitative agreement with the observed inter-glitch time-scales for the considered sample. Recoupling time-scales of the crustal superfluid are within the range of theoretical expectations and scale inversely with the spin-down rate of a pulsar. We also determined a braking index n = 2.63(30) for PSR J2229+6114 after glitch-induced contributions have been removed.
Disentangling the neighbouring pulsars SXP 15.3 and SXP 305
Authors: Monageng I M , Coe M J , Townsend L J , Laycock S G T , Kennea J A , Roy A , Udalski A , Bhattacharya S , Christodoulou D M , Buckley D A H , Evans P A 
Published: January 2022

ABSTRACT
SXP 15.3 and SXP 305 are two Be X-ray binaries in the Small Magellanic Cloud that are spatially separated by ∼7 arcsec. The small separation between these sources has, in the past, resulted in confusion about the origin of the emission from the combined region. We present long-term optical and X-ray monitoring results of both sources, where we study the historic and recent behaviour. In particular, from data collected as part of the S-CUBED project we see repeating X-ray outbursts from the combined region of the two sources in the recent light curve from the Neil Gehrels Swift Observatory, and we investigate the origin of this emission. Using the Hα emission line from the Southern African Large Telescope and photometric flux from the Optical Gravitational Lensing Experiment to study the changes in the size and structure of the Be disc, we demonstrate that the X-ray emission likely originates from SXP 15.3. Timing analysis reveals unusual behaviour, where the optical outburst profile shows modulation at approximately twice the frequency of the X-ray outbursts. We consider either of these periodicities being the true orbital period in SXP 15.3 and propose models based on the geometric orientations of the Be disc and neutron star to explain the physical origin of the outbursts.
The impact of faculae on the radius determination of exoplanets: the case of the M-star GJ 1214
Authors: Guenther Eike W 
Published: January 2022

ABSTRACT
Precise measurements of exoplanets radii are of key importance for our understanding of the origin and nature of these objects. Measurement of the planet radii using the transit method has reached a precision that the effects of stellar surface features have to be taken into account. While the effects from spots have already been studied in detail, our knowledge of the effects caused by faculae is still limited. This is particularly the case for M-stars. Faculae can pose a problem if they are inhomogeneously distributed on the stellar surface. Using the eclipse mapping method, we study the distribution of the faculae on the surface of GJ 1214 using the Ca ii H&K lines as tracers. In order to assess the homogeneity of the distribution in a quantitative way, we introduce the inhomogeneity factor (IHF). IHF is 0 per cent if the distribution is homogeneous, positive, if the plage regions are preferentially located along the path of the planet, and negative, if they are preferentially located outside the path of the planet. For GJ 1214, we derive a rather small value of $\rm IHF=7.7_{-7.7}^{+12.0}{{\ \rm per\ cent}}$. We discuss the relevance of this result in the context of the PLATO and ARIEL missions.
Cross-correlation of Planck cosmic microwave background lensing with DESI galaxy groups
Authors: Sun Zeyang , Yao Ji , Dong Fuyu , Yang Xiaohu , Zhang Le , Zhang Pengjie 
Published: January 2022

ABSTRACT
We measure the cross-correlation between galaxy groups constructed from DESI Legacy Imaging Survey DR8 and Planck cosmic microwave background (CMB) lensing, over overlapping sky area of 16 876 $\rm deg^2$. The detections are significant and consistent with the expected signal of the large-scale structure of Universe, over group samples of various redshift, mass, and richness Ng, and over various scale cuts. The overall signal-to-noise ratio is 40 for a conservative sample with Ng ≥ 5, and increases to 50 for the sample with Ng ≥ 2. Adopting the Planck 2018 cosmology, we constrain the density bias of groups with Ng ≥ 5 as bg = 1.31 ± 0.10, 2.22 ± 0.10, and 3.52 ± 0.20 at 0.1 &lt; z ≤ 0.33, 0.33 &lt; z ≤ 0.67, and 0.67 &lt; z ≤ 1, respectively. The group catalogue provides the estimation of group halo mass and therefore allows us to detect the dependence of bias on group mass with high significance. It also allows us to compare the measured bias with the theoretically predicted one using the estimated group mass. We find excellent agreement for the two high-redshift bins. However, it is lower than the theory by ∼3σ for the lowest redshift bin. Another interesting finding is the significant impact of the thermal Sunyaev Zel’dovich. It contaminates the galaxy group-CMB lensing cross-correlation at $\sim \! 30{{\ \rm per\ cent}}$ level, and must be deprojected first in CMB lensing reconstruction.
The bright extragalactic ALMA redshift survey (BEARS) I: redshifts of bright gravitationally lensed galaxies from the Herschel ATLAS
Authors: Urquhart S A , Bendo G J , Serjeant S , Bakx T , Hagimoto M , Cox P , Neri R , Lehnert M , Sedgwick C , Weiner C , Dannerbauer H , Amvrosiadis A , Andreani P , Baker A J , Beelen A , Berta S , Borsato E , Buat V , Butler K M , Cooray A , De Zotti G , Dunne L , Dye S , Eales S , Enia A , Fan L , Gavazzi R , González-Nuevo J , Harris A I , Herrera C N , Hughes D , Ismail D , Ivison R , Jin S , Jones B , Kohno K , Krips M , Lagache G , Marchetti L , Massardi M , Messias H , Negrello M , Omont A , Perez-Fournon I , Riechers D A , Scott D , Smith M W L , Stanley F , Tamura Y , Temi P , Vlahakis C , Weiß A , van der Werf P , Verma A , Yang C , Young A J 
Published: January 2022

ABSTRACT
We present spectroscopic measurements for 71 galaxies associated with 62 of the brightest high-redshift submillimetre sources from the Southern fields of the Herschel Astrophysical Terahertz Large Area Survey (H-ATLAS), while targeting 85 sources which resolved into 142. We have obtained robust redshift measurements for all sources using the 12-m Array and an efficient tuning of ALMA to optimize its use as a redshift hunter, with 73 per cent of the sources having a robust redshift identification. Nine of these redshift identifications also rely on observations from the Atacama Compact Array. The spectroscopic redshifts span a range 1.41 &lt; z &lt; 4.53 with a mean value of 2.75, and the CO emission line full-width at half-maxima range between $\rm 110\, km\, s^{-1} \lt FWHM \lt 1290\, km\, s^{-1}$ with a mean value of ∼500 km s−1, in line with other high-z samples. The derived CO(1-0) luminosity is significantly elevated relative to line-width to CO(1-0) luminosity scaling relation, which is suggestive of lensing magnification across our sources. In fact, the distribution of magnification factors inferred from the CO equivalent widths is consistent with expectations from galaxy–galaxy lensing models, though there is a hint of an excess at large magnifications that may be attributable to the additional lensing optical depth from galaxy groups or clusters.
Anisotropies of cosmic optical and near-IR background from the China space station telescope (CSST)
Authors: Cao Ye , Gong Yan , Liu Dezi , Cooray Asantha , Feng Chang , Chen Xuelei 
Published: January 2022

ABSTRACT
Anisotropies of the cosmic optical background (COB) and cosmic near-IR background (CNIRB) are capable of addressing some of the key questions in cosmology and astrophysics. In this work, we measure and analyse the angular power spectra of the simulated COB and CNIRB in the ultradeep field of the China Space Station Telescope (CSST-UDF). The CSST-UDF covers about 9 deg2, with magnitude limits ∼28.3, 28.2, 27.6, 26.7 AB mag for point sources with 5σ detection in the r (0.620 $\rm \mu m$), i (0.760 $\rm \mu m$), z (0.915 $\rm \mu m$), and y (0.965 $\rm \mu m$) bands, respectively. According to the design parameters and scanning pattern of the CSST, we generate mock data, merge images, and mask the bright sources in the four bands. We obtain four angular power spectra from ℓ = 200 to 2 000 000 (from arcsecond to degree), and fit them with a multicomponent model including intrahalo light (IHL) using the Markov chain Monte Carlo method. We find that, the signal-to-noise ratio of the IHL is larger than 8 over the range of angular scales that is useful for astrophysical studies (ℓ ∼10 000–400 000). Comparing to previous works, the constraints on the model parameters are improved by factors of 3∼4 in this study, which indicates that the CSST-UDF survey can be a powerful probe on the cosmic optical and near-IR backgrounds.
The extent of ionization in simulations of radio-loud AGNs impacting kpc gas discs
Authors: Meenakshi Moun , Mukherjee Dipanjan , Wagner Alexander Y , Nesvadba Nicole P H , Morganti Raffaella , Janssen Reinier M J , Bicknell Geoffrey V 
Published: January 2022

ABSTRACT
We use the results of relativistic hydrodynamic simulations of jet-interstellar medium (ISM) interactions in a galaxy with a radio-loud AGN to quantify the extent of ionization in the central few kpcs of the gaseous galactic disc. We perform post-process radiative transfer of AGN radiation through the simulated gaseous jet-perturbed disc to estimate the extent of photo-ionization by the AGN with an incident luminosity of 1045 erg s−1. We also map the gas that is collisionally ionized due to shocks driven by the jet. The analysis was carried out for simulations with similar jet power (1045 erg s−1) but different jet orientations with respect to the gas disc. We find that the shocks from the jets can ionize a significant fraction (up to 33 ${{\ \rm per\ cent}}$) of dense gas ($n\gt 100\, \mathrm{cm^{-3}}$) in the disc, and that the jets clear out the central regions of gas for AGN radiation to penetrate to larger distances in the disc. Jets inclined towards the disc plane couple more strongly with the ISM and ionize a larger fraction of gas in the disc as compared to the vertical jet. However, similar to previous studies, we find that the AGN radiation is quickly absorbed by the outer layers of dense clouds in the disc, and is not able to substantially ionize the disc on a global scale. Thus, compared to jet–ISM interactions, we expect that photo-ionization by the AGN radiation only weakly affects the star-formation activity in the central regions of the galactic disc (≲ 1 kpc), although the jet-induced shocks can spread farther out.
ExoPlaSim: Extending the Planet Simulator for exoplanets
Authors: Paradise Adiv , Macdonald Evelyn , Menou Kristen , Lee Christopher , Fan Bo Lin 
Published: January 2022

ABSTRACTThe discovery of a large number of terrestrial exoplanets in the habitable zones of their stars, many of which are qualitatively different from Earth, has led to a growing need for fast and flexible 3D climate models, which could model such planets and explore multiple possible climate states and surface conditions. We respond to that need by creating ExoPlaSim, a modified version of the Planet Simulator (PlaSim) that is designed to be applicable to synchronously rotating terrestrial planets, planets orbiting stars with non-solar spectra, and planets with non-Earth-like surface pressures. In this paper, we describe our modifications, present validation tests of ExoPlaSim’s performance against other GCMs, and demonstrate its utility by performing two simple experiments involving hundreds of models. We find that ExoPlaSim agrees qualitatively with more-sophisticated GCMs such as ExoCAM, LMDG, and ROCKE-3D, falling within the ensemble distribution on multiple measures. The model is fast enough that it enables large parameter surveys with hundreds to thousands of models, potentially enabling the efficient use of a 3D climate model in retrievals of future exoplanet observations. We describe our efforts to make ExoPlaSim accessible to non-modellers, including observers, non-computational theorists, students, and educators through a new Python API and streamlined installation through pip, along with online documentation.
High-precision star formation efficiency measurements in nearby clouds
Authors: Hu Zipeng , Krumholz Mark R , Pokhrel Riwaj , Gutermuth Robert A 
Published: January 2022

Abstract
On average molecular clouds convert only a small fraction εff of their mass into stars per free-fall time, but different star formation theories make contrasting claims for how this low mean efficiency is achieved. To test these theories, we need precise measurements of both the mean value and the scatter of εff, but high-precision measurements have been difficult because they require determining cloud volume densities, from which we can calculate free-fall times. Until recently, most density estimates treated clouds as uniform spheres, while their real structures are often filamentary and highly non-uniform, yielding systematic errors in εff estimates and smearing real cloud-to-cloud variations. We recently developed a theoretical model to reduce this error by using column density distributions in clouds to produce more accurate volume density estimates. In this work, we apply this model to recent observations of 12 nearby molecular clouds. Compared to earlier analyses, our method reduces the typical dispersion of εff within individual clouds from 0.16 dex to 0.12 dex, and decreases the median value of εff over all clouds from ≈0.02 to ≈0.01. However, we find no significant change in the ≈0.2 dex cloud-to-cloud dispersion of εff, suggesting the measured dispersions reflect real structural differences between clouds.
Probing the initial mass function of the first stars with transients
Authors: Lazar Alexandres , Bromm Volker 
Published: January 2022

ABSTRACT
The emergence of the first, so-called Population III (Pop III), stars shaped early cosmic history in ways that crucially depends on their initial mass function (IMF). However, because of the absence of direct observational constraints, the detailed IMF remains elusive. Nevertheless, numerical simulations agree in broad terms that the first stars were typically massive and should often end their lives in violent, explosive deaths. These fates include extremely luminous pair-instability supernovae (PISNe) and bright gamma-ray bursts (GRBs), the latter arising from the collapse of rapidly rotating progenitor stars into black holes. These high-redshift transients are expected to be within the detection limits of upcoming space telescope missions, allowing to place effective constraints on the shape of the primordial IMF that is not easily accessible with other probes. This paper presents a framework to probe the Pop III IMF, utilizing the cosmological source densities of high-redshift PISNe and GRBs. Considering these transients separately could provide useful constraints on the Pop III IMF, but tighter bounds are obtainable by combining PISN and GRB counts. This combined diagnostic is more robust as it is independent of the underlying Pop III star formation rate density, an unknown prior. Future surveys promise to capture most high-redshift GRBs across the entire sky, but high-redshift PISN searches with future telescopes, e.g. Roman Space Telescope, will likely be substantially incomplete. Nevertheless, we demonstrate that even such lower bounds on the PISN count will be able to provide key constraints on the primordial IMF, in particular, if it is top-heavy or not.
SN 2020kyg and the rates of faint Iax supernovae from ATLAS
Authors: Srivastav Shubham , Smartt S J , Huber M E , Chambers K C , Angus C R , Chen T-W , Callan F P , Gillanders J H , McBrien O R , Sim S A , Fulton M , Hjorth J , Smith K W , Young D R , Auchettl K , Anderson J P , Pignata G , de Boer T J L , Lin C-C , Magnier E A 
Published: January 2022

ABSTRACT
We present multiwavelength follow-up observations of the ATLAS discovered faint Iax supernova SN 2020kyg that peaked at an absolute magnitude of Mg ≈ −14.9 ± 0.2, making it another member of the faint Iax supernova population. The bolometric light curve requires only ≈7 × 10−3 M⊙ of radioactive 56Ni, with an ejected mass of Mej ∼ 0.4 M⊙ and a low kinetic energy of E ≈ 0.05 ± 0.02 × 1051 erg. We construct a homogeneous volume-limited sample of 902 transients observed by ATLAS within 100 Mpc during a 3.5 yr span. Using this sample, we constrain the rates of faint Iax (Mr ≳ −16) events within 60 Mpc at $12^{+14}_{-8}{{\ \rm per\ cent}}$ of the SN Ia rate. The overall Iax rate, at $15^{+17}_{-9}{{\ \rm per\ cent}}$ of the Ia rate, is dominated by the low-luminosity events, with luminous SNe Iax (Mr ≲ −17.5) like 2002cx and 2005hk, accounting for only $0.9^{+1.1}_{-0.5}{{\ \rm per\ cent}}$ of the Ia rate (a 2σ upper limit of approximately 3 per cent). We favour the hybrid CONe WD + He star progenitor channel involving a failed deflagration of a near Chandrasekhar mass white dwarf, expected to leave a bound remnant and a surviving secondary companion, as a candidate explanation for faint Iax explosions. This scenario requires short delay times, consistent with the observed environments of SNe Iax. Furthermore, binary population synthesis calculations have suggested rates of $1\!-\!18{{\ \rm per\ cent}}$ of the SN Ia rate for this channel, consistent with our rate estimates.
Dynamics of intermediate-mass black holes wandering in the milky way galaxy using the illustris TNG50 simulation
Authors: Weller Emma Jane , Pacucci Fabio , Hernquist Lars , Bose Sownak 
Published: January 2022

ABSTRACT
The detection of Intermediate-Mass Black Holes (IMBHs) in dwarf galaxies is crucial to closing the gap in the wide mass distribution of black holes ($\sim 3 \, {\rm M_\odot }$ to $\sim 5 \times 10^{10} \, {\rm M_\odot }$). IMBHs originally located at the centre of dwarfs that later collide with the Milky Way (MW) could be wandering, undetected, in our Galaxy. We used TNG50, the highest resolution run of the IllustrisTNG project, to study the kinematics and dynamics of star clusters, in the appropriate mass range, acting as IMBH proxies in an MW analogue galaxy. We showed that $\sim 87{{\ \rm per\ cent}}$ of our studied IMBHs drift inward. The radial velocity of these sinking IMBHs has a median magnitude of $\sim 0.44 \, \mathrm{ckpc \, h^{-1} \, Gyr^{-1}}$ and no dependence on the black hole mass. The central $1 \, \rm ckpc \, h^{-1}$ has the highest number density of IMBHs in the galaxy. A physical toy model with linear drag forces was developed to explain the orbital circularization with time. These findings constrain the spatial distribution of IMBHs, suggesting that future searches should focus on the central regions of the Galaxy. Additionally, we found that the 3D velocity distribution of IMBHs with respect to the galactic centre has a mean of $\sim 180 \, \mathrm{km \, s^{-1}}$ and larger variance with decreasing radius. Remarkably, the velocity distribution relative to the local gas shows significantly lower values, with a mean of $\sim 88 \, \mathrm{km \, s^{-1}}$. These results are instrumental for predicting the accretion and radiation properties of IMBHs, facilitating their detection with future surveys.
The puzzling story of flare inactive ultra fast rotating M dwarfs. II. Searching for radial velocity variations
Authors: Ramsay Gavin , Hakala Pasi , Doyle J Gerry , Doyle Lauren , Bagnulo Stefano 
Published: January 2022

ABSTRACT
Observations made using TESS revealed a sample of low-mass stars which show a periodic modulation on a period &lt;0.2 d. Surprisingly, many of these ultra fast rotating (UFR) stars showed no evidence of flare activity which would be expected from such rapidly rotating stars. We present results from a spectroscopic survey of UFRs using the Nordic Optical Telescope to search for radial velocity variations which could reveal evidence for binarity. Our sample of 29 sources have a photometric period between 0.1–0.2 d, cover spectral classes of M0-4V, and show no evidence for flares. We detect only one source with clear radial velocity shifts, with another two having Gaia RUWE values which suggests they are binaries. Further observations reveal the former star possibly contains a brown dwarf companion with a mass of M2 &gt; 58 MJup and probability P(M2 &lt; 90 MJup) = 50 per cent. There is no evidence for the companion in our spectra, strengthening the case for a brown dwarf companion. We also examine the folded TESS light curves of all our targets, finding at least two are eclipsing binaries and one which has been contaminated by a spatially nearby δ Sct star. We estimate that around 1/4 of our targets may have been contaminated by short period variable stars. However, the majority of our targets are consistent with being single, low mass stars whose variability is due to starspots. We outline the possible reasons why they are not flare active despite being such rapid rotators.
Mysterious odd radio circle near the large magellanic cloud – an intergalactic supernova remnant?
Authors: Filipović Miroslav D , Payne J L , Alsaberi R Z E , Norris R P , Macgregor P J , Rudnick L , Koribalski B S , Leahy D , Ducci L , Kothes R , Andernach H , Barnes L , Bojičić I S , Bozzetto L M , Brose R , Collier J D , Crawford E J , Crocker R M , Dai S , Galvin T J , Haberl F , Heber U , Hill T , Hopkins A M , Hurley-Walker N , Ingallinera A , Jarrett T , Kavanagh P J , Lenc E , Luken K J , Mackey D , Manojlović P , Maggi P , Maitra C , Pennock C M , Points S , Riggi S , Rowell G , Safi-Harb S , Sano H , Sasaki M , Shabala S , Stevens J , van Loon J Th , Tothill N F H , Umana G , Urošević D , Velović V , Vernstrom T , West J L , Wan Z 
Published: January 2022

ABSTRACT
We report the discovery of J0624–6948, a low-surface brightness radio ring, lying between the Galactic Plane and the large magellanic cloud (LMC). It was first detected at 888 MHz with the Australian Square Kilometre Array Pathfinder (ASKAP), and with a diameter of ∼196 arcsec. This source has phenomenological similarities to odd radio circles (ORCs). Significant differences to the known ORCs – a flatter radio spectral index, the lack of a prominent central galaxy as a possible host, and larger apparent size – suggest that J0624–6948 may be a different type of object. We argue that the most plausible explanation for J0624–6948 is an intergalactic supernova remnant due to a star that resided in the LMC outskirts that had undergone a single-degenerate type Ia supernova, and we are seeing its remnant expand into a rarefied, intergalactic environment. We also examine if a massive star or a white dwarf binary ejected from either galaxy could be the supernova progenitor. Finally, we consider several other hypotheses for the nature of the object, including the jets of an active galactic nucleus (30Dor) or the remnant of a nearby stellar super-flare.