We present the discovery and timing of the young (age ∼28.6 kyr) pulsar PSR J0837–2454. Based on its high latitude (b = 9.8) and dispersion measure (DM = 143 pc cm−3), the pulsar appears to be at a z-height of >1 kpc above the Galactic plane, but near the edge of our Galaxy. This is many times the observed scale height of the canonical pulsar population, which suggests this pulsar may have been born

We present deep (265 ks) Chandra X-ray observations of PSO J352.4034−15.3373, a quasar at z = 5.831 that, with a radio-to-optical flux ratio of R > 1000, is one of the radio-loudest quasars in the early universe and is the only quasar with observed extended radio jets of kiloparsec scale at z ≳ 6. Modeling the X-ray spectrum of the quasar with a power law, we find a best fit of , leading to an X-ray

To study acoustic wave propagation and the corresponding energy deposition in partially ionized plasmas, we use a two-fluid computational model that treats neutrals and charged particles (electrons and ions) as two separate fluids. This two-fluid model takes into account the ion–neutral collisions, ionization, and recombination, allowing us to investigate both the collisional and reactive interactions

Global EUV waves remain a controversial phenomenon more than 20 yr after their discovery by SOHO/EIT. Although consensus is growing in the community that they are most likely large-amplitude waves or shocks, the wide variety of observations and techniques used to identify and analyze them have led to disagreements regarding their physical properties and interpretation. Here, we use a 3D magnetohydrodynamic

There is growing evidence that the population of close-in planets discovered by the Kepler mission was sculpted by atmospheric loss, though the typical timescale for this evolution is not well-constrained. Among a highly complete sample of planet hosts of varying ages the age-dependence of the relative fraction of super-Earth and sub-Neptune detections can be used to constrain the rate at which some

Using the N-body+Smoothed particle hydrodynamics code, ChaNGa, we identify two merger-driven processes—disk disruption and supermassive black hole (SMBH) feedback—which work together to quench L * galaxies for over 7 Gyr. Specifically, we examine the cessation of star formation in a simulated Milky Way (MW) analog, driven by an interaction with two minor satellites. Both interactions occur within ∼100

Subpercent level accuracy in shear measurement is required by the Stage-IV weak lensing surveys. One important challenge is suppressing the shear bias on source images of low signal-to-noise ratios (S/N ≲ 10). Previously, it has been demonstrated that the shear estimators defined in the Fourier_Quad (FQ) method can achieve subpercent accuracy at the very faint end (S/N ≲ 5) through ensemble averaging

The collisional growth of dust grains in a protoplanetary nebula is impacted by sintering because this increases the elasticity of the neck between dust grains. The high elasticity of a neck can lead to bouncing and not sticking of dust aggregates. This hinders the formation of planetesimals, and dust aggregates accumulate at a particular location in a protoplanetary nebula. Following sintering, the

Using the data sets of Mars Atmosphere and Volatile EvolutioN and OMNI for the period 2014 October 10–2020 February 14 and the heliocentric distance of 1–1.66 au, we investigate the statistical properties of solar wind upstream of Mars for the first time. The key parameters, including interplanetary magnetic field (IMF), proton density (N), bulk velocity (∣ V ∣), and dynamic pressure (P dyn), are surveyed

The H i Lyα (1215.67 Å) emission line dominates the far-UV spectra of M dwarf stars, but strong absorption from neutral hydrogen in the interstellar medium makes observing Lyα challenging even for the closest stars. As part of the Far-Ultraviolet M-dwarf Evolution Survey, the Hubble Space Telescope has observed 10 early-to-mid M dwarfs with ages ranging from ∼24 Myr to several Gyr in order to evaluate

M-dwarf stars are prime targets for exoplanet searches because of their close proximity and favorable properties for both planet detection and characterization. However, the potential habitability and atmospheric characterization of these exoplanetary systems depends critically on the history of high-energy stellar radiation from X-rays to NUV, which drive atmospheric mass loss and photochemistry in

We present bright [C ii] 158 μm line detections from a strongly magnified and multiply imaged (μ ∼ 20–160) sub–L * () Lyman-break galaxy (LBG) at z = 6.0719 0.0004, drawn from the ALMA Lensing Cluster Survey (ALCS). Emission lines are identified at 268.7 GHz at ≥8σ exactly at the positions of two multiple images of the LBG, behind the massive galaxy cluster RXCJ0600−2007. Our lens models, updated with

Relic gravitational waves (GWs) can be produced by primordial magnetic fields. However, not much is known about the resulting GW amplitudes and their dependence on the details of the generation mechanism. Here we treat magnetic field generation through the chiral magnetic effect (CME) as a generic mechanism and explore its dependence on the speed of generation (the product of magnetic diffusivity and

We present a search for RR Lyrae stars using the full six-year data set from the Dark Energy Survey covering ∼5000 deg2 of the southern sky. Using a multistage multivariate classification and light-curve template-fitting scheme, we identify RR Lyrae candidates with a median of 35 observations per candidate. We detect 6971 RR Lyrae candidates out to ∼335 kpc, and we estimate that our sample is >70%

The Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) is an unbiased, massively multiplexed spectroscopic survey, designed to measure the expansion history of the universe through low-resolution (R ∼ 750) spectra of Lyα emitters. In its search for these galaxies, HETDEX will also observe a few times 105 stars. In this paper, we present the first stellar value-added catalog within the internal

By combining the Large Sky Area Multi-object Fiber Spectroscopic Telescope and Gaia data, we investigate the vertical phase mixing across the Galactic disk. Our results confirm the existence of phase space snail shells (or phase spirals) from 6–12 kpc. We find that grouping stars by the guiding radius (R g ), instead of the present radius (R), further enhances the snail shell signal in the following

Filamentary structures are recognized as a fundamental component of interstellar molecular clouds in observations made by the Herschel satellite. These filaments, especially massive filaments, often extend in a direction perpendicular to the interstellar magnetic field. Furthermore, the filaments sometimes have an apparently negative temperature gradient—that is, their temperatures decrease toward

Compact groups (CGs) of galaxies appear to be the densest galaxy systems containing a few luminous galaxies in close proximity to each other, which have a typical size of a few tens of kiloparsec in observation. On the other hand, in the modern hierarchical structure formation paradigm, galaxies are assembled and grouped in dark matter halos, which have a typical size of a few hundreds of kiloparsec

Observational evidence suggests that the majority of stars may have been born in stellar clusters or associations. Within these dense environments, dynamical interactions lead to high rates of close stellar encounters. A variety of recent observational and theoretical indications suggest stellar-mass black holes may be present and play an active dynamical role in stellar clusters of all masses. In

R Coronae Borealis (RCB) stars are rare hydrogen-deficient carbon-rich variable supergiants thought to be the result of dynamically unstable white dwarf mergers. We attempt to model RCB stars through all the relevant timescales by simulating a merger event in Octo-tiger, a 3D adaptive mesh refinement (AMR) hydrodynamics code, and mapping the post-merger object into MESA, a 1D stellar evolution code

Fast radio bursts (FRBs) can be scattered by ionized gas in their local environments, host galaxies, intervening galaxies along their lines of sight (LOS), the intergalactic medium, and the Milky Way. The relative contributions of these different media depend on their geometric configuration and the internal properties of the gas. When these relative contributions are well understood, FRB scattering

Thorne–Żytkow objects (TŻOs) are a class of stellar object comprised of a neutron star core surrounded by a large and diffuse envelope. Their exterior appearance is identical to red supergiants; the distinctive electromagnetic signature of a TŻO is a suite of unusual chemical abundance patterns, including excesses of Li, Rb, Mo, and Ca. However, electromagnetic observations cannot unambiguously identify

We present integral field spectroscopic observations of the nearby (z ∼ 0.03) dual active galactic nuclei (AGNs) Mrk 739, whose projected nuclear separation is ∼3.4 kpc, obtained with the Multi Unit Spectroscopic Explorer at the Very Large Telescope. We find that the galaxy has an extended AGN-ionized emission-line region extending up to ∼20 kpc away from the nuclei, while star-forming regions are

This paper systematically investigates the comoving megaparsec-scale intergalactic medium (IGM) environment around galaxies traced by the Lyα forest. Using our cosmological hydrodynamic simulations, we investigate the IGM–galaxy connection at z = 2 by two methods: (i) cross-correlation analysis between galaxies and the fluctuation of Lyα forest transmission (δ F) and (ii) comparison of the overdensity

The merger of binary neutron stars (NS–NS) as the progenitor of short gamma-ray bursts (GRBs) has been confirmed by the discovery of the association of the gravitational-wave (GW) event GW170817 with GRB 170817A. However, the merger product of binary NS remains an open question. An X-ray plateau followed by a steep decay (“internal plateau”) has been found in some short GRBs, implying that a supramassive

In the next decade, transient searches from the Vera C. Rubin Observatory and the Nancy Grace Roman Space Telescope will increase the sample of known Type Ia supernovae (SNe Ia) from ∼103 to 105. With this reduction of statistical uncertainties on cosmological measurements, new methods are needed to reduce systematic uncertainties. Characterizing the underlying spectroscopic evolution of SN Ia remains

We introduce a new method to estimate the probability that an extragalactic transient source is associated with a candidate host galaxy. This approach relies solely on simple observables: sky coordinates and their uncertainties, galaxy fluxes, and angular sizes. The formalism invokes Bayes’ rule to calculate the posterior probability from the galaxy prior P(O), observables x, and an assumed model for

We present rest-frame B and I imaging of 35 low-redshift () Palomar–Green quasars using the Hubble Space Telescope Wide Field Camera 3. We perform multicomponent two-dimensional image decomposition to separate the host galaxy from its bright active nucleus, characterize its morphology, and measure its photometric properties. Special care is devoted to quantifying the structural parameters of the galaxy

This project aims to investigate the most important weak interaction nuclei in the presupernova evolution of massive stars. To achieve this goal, an ensemble containing 728 nuclei in the mass range of A = 1–100 was considered. We computed the mass fractions of these nuclei using Saha’s equation for predetermined values of T, ρ, and Y e and assuming nuclear statistical equilibrium. The nuclear partition

We report on the discovery of a promising candidate for a black widow (BW) millisecond pulsar binary, 4FGL J0336.0+7502, which shows many pulsar-like properties in the 4FGL-DR2 catalog. Within the 95% error region of the LAT source, we identified an optical counterpart with a clear periodicity at P orb = 3.718178(9) hr using the Bohyunsan 1.8 m Telescope, the Lulin One-meter Telescope, the Canada–France–Hawaii

We have investigated the stellar and interstellar content of the distant star formation region IRAS 17591-2228 (WISE H ii region GAL 007.47+0.06). It is associated with a water maser, whose parallax distance is kpc, supported by independent measurements of proper motion and radial velocity. It is projected in the same direction as an extremely red (J−K S ∼ 6 mag) group of stars, and a shell of mid-infrared

Using a 3D global solver of the linearized Euler equations, we model acoustic oscillations over background velocity flow fields of single-cell meridional circulation with deep and shallow return flows as well as double-cell meridional circulation with strong and weak reversals. The velocities are generated using a mean-field hydrodynamic and dynamo model—moving through the regimes with minimal parameter

Nonlinear ion-acoustic waves, ion holes, and electron holes have been observed on the Parker Solar Probe at a heliocentric distance of 35 solar radii. These time domain structures contain millisecond duration electric field spikes of several mV m−1. They are observed inside or at boundaries of switchbacks in the background magnetic field. Their presence in switchbacks indicates that both electron-

We use the FIRE-2 cosmological simulations to study the formation of a quasi-static, virial-temperature gas phase in the circumgalactic medium (CGM) at redshifts 0 < z < 5 and how the formation of this virialized phase affects the evolution of galactic disks. We demonstrate that when the halo mass crosses ∼1012 M ⊙, the cooling time of shocked gas in the inner CGM (∼0.1R vir, where R vir is the virial

Compact binary mergers that involve at least one neutron star, either binary neutron star or black hole–neutron star coalescences, are thought to be the potential sources of electromagnetic emission due to the material ejected during the merger or those left outside the central object after the merger. Since the intensity of these electromagnetic transients decays rapidly with time, one should pay

We analyze the coronal elemental abundances during a small flare using Hinode/EIS observations. Compared to the preflare elemental abundances, we observed a strong increase in coronal abundance of Ca xiv 193.84 Å, an emission line with low first ionization potential (FIP < 10 eV), as quantified by the ratio Ca/Ar during the flare. This is in contrast to the unchanged abundance ratio observed using

In this work, we present simulations of thin accretion disks around black holes, in order to investigate a mean-field disk dynamo, using our resistive GRMHD code, which is able to produce a large-scale magnetic flux. We consider a weak seed field in an initially thin disk, a background (turbulent) magnetic diffusivity, and the dynamo action itself. A standard quenching mechanism is applied to mitigate

We present analytic estimates of the fractional uncertainties on the mass, radius, surface gravity, and density of a transiting planet, using only empirical or semi-empirical measurements. We first express these parameters in terms of transit photometry and radial velocity (RV) observables, as well as the stellar radius R ⋆, if required. In agreement with previous results, we find that, assuming a

The choice of the optimal value of the softening length (ϵ i ) of each particle dealing with N-body simulations has a profound impact on error values in the gravitational force calculation. A slight deviation from its exact optimal value may result in a large error in the calculation. In this paper we augment the accuracy of the existing gravitational force calculation methods by providing a new technique

In recent years, the availability of large, complete cluster samples has enabled numerous cosmological parameter inference analyses using cluster number counts. These have provided constraints on the cosmic matter density Ω m and the amplitude of matter density fluctuations σ 8 alternative to that obtained from other standard probes. However, systematics uncertainties, such as the mass calibration

Magnetic fields are ubiquitous and essential in star formation. In particular, their role in regulating formation of stars across diverse environments like H ii regions needs to be well understood. In this study, we present magnetic field properties toward the S235 complex using near-infrared (NIR) H-band polarimetric observations, obtained with the Mimir and POLICAN instruments. We selected 375 background

In this paper we test if the ∼0.3–15 keV XMM-Newton EPIC pn spectral continuum of IPs can be described by the thermal Comptonization compTT model. We used publicly observations of 12 IPs (AE Aqr, EX Hya, V1025 Cen, V2731 Oph, RX J2133.7+5107, PQ Gem, NY Lup, V2400 Oph, IGR J00234+6141, IGR J17195-4100, V1223 Sgr, and XY Ari). We find that our modeling is capable of fitting well the average spectral

In our earlier study (Paper I) of this series, we examined the hemispheric sign preference (HSP) of magnetic helicity flux dH/dt across photospheric surfaces of 4802 samples of 1105 unique active regions (ARs) observed during solar cycle 24. Here, we investigate any association of the HSP, expressed as a degree of compliance, with flaring activity, analyzing the same set of dH/dt estimates as used

We present a new catalog of 9318 Lyα emitter (LAE) candidates at z = 2.2, 3.3, 4.9, 5.7, 6.6, and 7.0 that are photometrically selected by the SILVERRUSH program with a machine learning technique from large area (up to 25.0 deg2) imaging data with six narrowband filters taken by the Subaru Strategic Program with Hyper Suprime-Cam and a Subaru intensive program, Cosmic HydrOgen Reionization Unveiled

We present a sensitive search with the Karl G. Jansky Very Large Array for the radio counterpart of the gravitational wave candidate S191216ap, which is classified as a binary black hole merger and suggested to be a possible multimessenger event, based on the detection of a high-energy neutrino and a TeV photon. We carried out a blind search at C band (4–8 GHz) over 0.3 deg2 of the gamma-ray counterpart

As the central engine of gamma-ray bursts (GRBs), a nascent magnetar can release its rotational energy by magnetic dipole radiation. This energy is injected into the outflow of the GRB jet. With the rapid evolution of the magnetic inclination angle, the perpendicular component of the magnetar’s surface magnetic field decreases rapidly. The energy loss rate of the magnetar is characterized by two different

The recent rediscovery of magnetic field switchbacks or deflections embedded in the solar wind flow by the Parker Solar Probe mission lead to a huge interest in the modeling of the formation mechanisms and origin of these switchbacks. Several scenarios for their generation were put forth, ranging from lower solar atmospheric origins by reconnection, to being a manifestation of turbulence in the solar

We study the consequences of a hadron-quark phase transition (PT) in failing core-collapse supernovae (CCSNe) that give birth to stellar-mass black holes (BH). We perform a suite of neutrino-transport general-relativistic hydrodynamic simulations in spherical symmetry with 21 progenitor models and a hybrid equation of state (EoS) including hadrons and quarks. We find that the effect of the PT on the

Switchbacks are widely acknowledged phenomena observed by the Parker Solar Probe and appear to occur in patches. Previous studies focused on the fluctuations at the magnetic reversals. However, the nature of the fluctuations inside the switchbacks remains unknown. Here we utilize the magnetic field data and plasma data measured by the Parker Solar Probe in the first four encounters. We investigate

In the stellar chromospheres, radiative energy transport is dominated by only the strongest spectral lines. For these lines, the approximation of local thermodynamic equilibrium (LTE) is known to be very inaccurate, and a state of equilibrium cannot be assumed in general. To calculate the radiative energy transport under these conditions, the population evolution equation must be evaluated explicitly

We have obtained Keck near-infrared spectroscopy of a sample of nine M ⋆ < 1010 M ⊙ dwarf galaxies to confirm active galactic nuclei (AGNs) activity and the presence of galaxy-wide, AGN-driven outflows through coronal line (CL) emission. We find strong CL detections in 5/9 galaxies (55%) with line ratios incompatible with shocks, confirming the presence of AGNs in these galaxies. Similar CL detection

Massive star formation occurs in the interior of giant molecular clouds and proceeds through many stages. In this work, we focus on massive young stellar objects (MYSOs) and ultracompact H ii regions (UCH ii), where the former are enshrouded in dense envelopes of dust and gas, the latter of which has begun dispersing. By selecting a complete sample of MYSOs and UCH ii from the Red MSX Source (RMS)

Ram pressure stripping can remove gas from satellite galaxies in clusters via a direct interaction between the intracluster medium (ICM) and the interstellar medium. This interaction is generally thought of as a contact force per area; however, we point out that these gases must interact in a hydrodynamic fashion and argue that this will lead to the mixing of the galactic gas with the ICM wind. We

High-energy neutrinos are unique messengers of the high-energy universe, tracing the processes of cosmic ray acceleration. This paper presents analyses focusing on time-dependent neutrino point-source searches. A scan of the whole sky, making no prior assumption about source candidates, is performed, looking for a space and time clustering of high-energy neutrinos in data collected by the IceCube Neutrino

We present a multiwavelength analysis of the cluster A1668, performed by means of new EVLA and Chandra observations and archival Hα data. The radio images exhibit a small central source (∼14 kpc at 1.4 GHz) with L 1.4GHz ∼ 6 1023 W Hz−1. The mean spectral index between 1.4 GHz and 5 GHz is ∼−1, consistent with the usual indices found in BCGs. The cooling region extends for 40 kpc, with bolometric X-ray

We present a measurement of the Hubble constant H 0 from surface brightness fluctuation (SBF) distances for 63 bright, mainly early-type galaxies out to 100 Mpc observed with the WFC3/IR on the Hubble Space Telescope (HST). The sample is drawn from several independent HST imaging programs using the F110W bandpass, with the majority of the galaxies being selected from the MASSIVE survey. The distances

We present the first results of a 4.5 yr monitoring campaign of the three bright images of multiply imaged z = 2.805 quasar SDSS J2222+2745 using the Gemini North Multi-Object Spectrograph and the Nordic Optical Telescope. We take advantage of gravitational time delays to construct light curves surpassing 6 yr in duration in the observed frame and achieve an average spectroscopic cadence of 10 days

We present a study of density fluctuations in coronal holes. We used a reduced magnetohydrodynamic (RMHD) model that incorporated observationally constrained density fluctuations to determine whether density fluctuations in coronal holes can enhance Alfvn wave reflection and dissipation, thereby heating coronal holes and driving the fast solar wind. We show results for two models of the background

We present new WFC3/UVIS observations of UGC4483, the closest example of a metal-poor blue compact dwarf galaxy, with a metallicity of Z≃1/15 Z ⊙ and located at a distance of D≃3.4 Mpc. The extremely high quality of our new data allows us to clearly resolve the multiple stellar evolutionary phases populating the color–magnitude diagram (CMD), to reach more than 4 mag deeper than the tip of the red

Voyager 1 has been moving through the very local interstellar medium (VLISM) from the time that it crossed the heliopause on 2012/DOY 238 to 2020/DOY 292. Three notable objects in the magnetic field of the VLISM have been observed: two shocks and one pressure front. This paper reports the observation of a fourth object observed near 2020/DOY 147. There were no upstream electron plasma oscillations