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  • Analytical Solution of Magnetically Dominated Astrophysical Jets and Winds: Jet Launching, Acceleration, and Collimation
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-13
    Liang Chen and Bing Zhang

    We present an analytical solution of a highly magnetized jet/wind flow. The left side of the general force-free jet/wind equation (the “pulsar” equation) is separated into a rotating and a nonrotating term. The two equations with either term can be solved analytically, and the two solutions match each other very well. Therefore, we obtain a general approximate solution of a magnetically dominated jet/wind

    更新日期:2021-01-13
  • Fundamental Reference AGN Monitoring Experiment (FRAMEx). I. Jumping Out of the Plane with the VLBA
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-13
    Travis C. Fischer, Nathan J. Secrest, Megan C. Johnson, Bryan N. Dorland, Phillip J. Cigan, Luis C. Fernandez, Lucas R. Hunt, Michael Koss, Henrique R. Schmitt, and Norbert Zacharias

    We present the first results from the Fundamental Reference active galactic nucleus (AGN) Monitoring Experiment, an observational campaign dedicated to understanding the physical processes that affect the apparent positions and morphologies of AGNs. In this work, we obtained simultaneous Swift X-ray Telescope and Very Long Baseline Array (VLBA) radio observations for a snapshot campaign of 25 local

    更新日期:2021-01-13
  • Can the Helium-detonation Model Explain the Observed Diversity of Type Ia Supernovae?
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-13
    Wenxiong Li, Xiaofeng Wang, Mattia Bulla, Yen-Chen Pan, Lifan Wang, Jun Mo, Jujia Zhang, Chengyuan Wu, Jicheng Zhang, Tianmeng Zhang, Danfeng Xiang, Han Lin, Hanna Sai, Xinghan Zhang, Zhihao Chen, and Shengyu Yan

    We study a sample of 16 Type Ia supernovae (SNe Ia) having both spectroscopic and photometric observations within 2–3 days after the first light. The early B − V colors of such a sample tend to show a continuous distribution. For objects with normal ejecta velocity (NV), theC ii λ 6580 feature is always visible in the early spectra, while it is absent or very weak in the high-velocity (HV) counterpart

    更新日期:2021-01-13
  • Void Galaxies Follow a Distinct Evolutionary Path in the Environmental COntext Catalog
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-13
    Jonathan Florez, Andreas A. Berlind, Sheila J. Kannappan, David V. Stark, Kathleen D. Eckert, Victor F. Calderon, Amanda J. Moffett, Duncan Campbell, and Manodeep Sinha

    We measure the environmental dependence, where environment is defined by the distance to the third nearest neighbor, of multiple galaxy properties inside the Environmental COntext (ECO) catalog. We focus primarily on void galaxies, which we define as the 10% of galaxies having the lowest local density. We compare the properties of void and non-void galaxies: baryonic mass, color, fractional stellar

    更新日期:2021-01-13
  • The Dispersion Measure and Scattering of Fast Radio Bursts: Contributions from the Intergalactic Medium, Foreground Halos, and Hosts
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-13
    Weishan Zhu and Long-Long Feng

    We investigate the dispersion measure (DM) and scattering of fast radio bursts (FRBs) by the intergalactic medium (IGM), foreground halos, and host halos using cosmological hydrodynamical simulation. We find that the median DM caused by foreground halos is around 30% of that caused by the IGM, but it has a much larger variance. The DM induced by hosts deviates from a log-normal distribution but exhibits

    更新日期:2021-01-13
  • Evolution of Three-dimensional Coherent Structures in Hall Magnetohydrodynamics
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-13
    K. Bora, R. Bhattacharyya, and P. K. Smolarkiewicz

    This work extends the computational model EULAG-MHD to include Hall magnetohydrodynamics (HMHD)—important to explore physical systems undergoing fast magnetic reconnection at the order of the ion inertial length scale. Examples include solar transients along with reconnections in magnetosphere, magnetotail, and laboratory plasmas. The paper documents the results of two distinct sets of implicit large-eddy

    更新日期:2021-01-13
  • Ultrafaint Dwarfs in a Milky Way Context: Introducing the Mint Condition DC Justice League Simulations
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-13
    Elaad Applebaum, Alyson M. Brooks, Charlotte R. Christensen, Ferah Munshi, Thomas R. Quinn, Sijing Shen, and Michael Tremmel

    We present results from the “Mint” resolution DC Justice League suite of Milky Way–like zoom-in cosmological simulations, which extend our study of nearby galaxies down into the ultrafaint dwarf (UFD) regime for the first time. The mass resolution of these simulations is the highest ever published for cosmological Milky Way zoom-in simulations run to z = 0, with initial star (dark matter) particle

    更新日期:2021-01-13
  • The SAMI Galaxy Survey: Bulge and Disk Stellar Population Properties in Cluster Galaxies
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-13
    S. Barsanti, M. S. Owers, R. M. McDermid, K. Bekki, J. Bland-Hawthorn, S. Brough, J. J. Bryant, L. Cortese, S. M. Croom, C. Foster, J. S. Lawrence, Á. R. López-Sánchez, S. Oh, A. S. G. Robotham, N. Scott, S. M. Sweet, and J. van de Sande

    We explore stellar population properties separately in the bulge and the disk of double-component cluster galaxies, to shed light on the formation of lenticular galaxies in dense environments. We study eight low-redshift clusters from the Sydney-AAO Multi-object Integral field Galaxy Survey, using two-dimensional photometric bulge–disk decomposition in the g , r , and i bands to characterize galaxies

    更新日期:2021-01-13
  • An Energy Inventory of Tidal Disruption Events
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-13
    Brenna Mockler and Enrico Ramirez-Ruiz

    Tidal disruption events (TDEs) offer a unique opportunity to study a single supermassive black hole (SMBH) under feeding conditions that change over timescales of days to months. However, the primary mechanism for generating luminosity during the flares remains debated. Despite the increasing number of observed TDEs, it is unclear whether most of the energy in the initial flare comes from accretion

    更新日期:2021-01-13
  • The Effects of Biconical Outflows on Ly α Escape from Green Peas
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-13
    Cody Carr, Claudia Scarlata, Alaina Henry, and Nino Panagia

    We analyze the spectra of 10 Green Pea galaxies, previously studied by Henry et al., using a semi-analytical line transfer model to interpret emission and absorption features observed in UV galactic spectra. We focus our analysis on various ionization states of silicon, associated with the cool (∼10 4 K) and warm (∼10 5 K) gas. By analyzing low-ionization lines, we study the relationships between the

    更新日期:2021-01-13
  • The Sloan Digital Sky Survey Reverberation Mapping Project: The M BH –Host Relations at0.2 ≲ z ≲ 0.6 from Reverberation Mapping and Hubble Space Telescope Imaging
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-13
    Jennifer I-Hsiu Li, Yue Shen, Luis C. Ho, W. N. Brandt, Elena Dalla Bontà, G. Fonseca Alvarez, C. J. Grier, J. V. Hernandez Santisteban, Y. Homayouni, Keith Horne, B. M. Peterson, D. P. Schneider, and Jonathan R. Trump

    We present the results of a pilot Hubble Space Telescope (HST) imaging study of the host galaxies of ten quasars from the Sloan Digital Sky Survey Reverberation Mapping (SDSS-RM) project. Probing more than an order of magnitude in black hole (BH) and stellar masses, our sample is the first statistical sample to study the BH–host correlations beyond z > 0.3 with reliable BH masses from reverberation

    更新日期:2021-01-13
  • Numerical Relativity Simulations of the Neutron Star Merger GW170817: Long-term Remnant Evolutions, Winds, Remnant Disks, and Nucleosynthesis
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-13
    Vsevolod Nedora, Sebastiano Bernuzzi, David Radice, Boris Daszuta, Andrea Endrizzi, Albino Perego, Aviral Prakash, Mohammadtaher Safarzadeh, Federico Schianchi, and Domenico Logoteta

    We present a systematic numerical relativity study of the dynamical ejecta, winds, and nucleosynthesis in neutron star (NS) merger remnants. Binaries with the chirp mass compatible with GW170817, different mass ratios, and five microphysical equations of state (EOSs) are simulated with an approximate neutrino transport and a subgrid model for magnetohydrodynamic turbulence up to 100 ms postmerger.

    更新日期:2021-01-13
  • ALMA and IRIS Observations of the Solar Chromosphere. I. An On-disk Type II Spicule
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-12
    Georgios Chintzoglou, Bart De Pontieu, Juan Martínez-Sykora, Viggo Hansteen, Jaime Cruz de la Rodríguez, Mikolaj Szydlarski, Shahin Jafarzadeh, Sven Wedemeyer, Timothy S. Bastian, and Alberto Sainz Dalda

    We present observations of the solar chromosphere obtained simultaneously with the Atacama Large Millimeter/submillimeter Array (ALMA) and the Interface Region Imaging Spectrograph. The observatories targeted a chromospheric plage region of which the spatial distribution (split between strongly and weakly magnetized regions) allowed the study of linear-like structures in isolation, free of contamination

    更新日期:2021-01-12
  • GPCAL: A Generalized Calibration Pipeline for Instrumental Polarization in VLBI Data
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-12
    Jongho Park, Do-Young Byun, Keiichi Asada, and Youngjoo Yun

    We present the Generalized Polarization CALibration pipeline (GPCAL), an automated pipeline for instrumental polarization calibration of very long baseline interferometry (VLBI) data. The pipeline is designed to achieve a high calibration accuracy by means of fitting the instrumental polarization model, including the second-order terms, to data from multiple calibrator sources simultaneously. It also

    更新日期:2021-01-12
  • From Supernova to Supernova Remnant: Comparison of Thermonuclear Explosion Models
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-12
    Gilles Ferrand, Donald C. Warren, Masaomi Ono, Shigehiro Nagataki, Friedrich K. Röpke, Ivo R. Seitenzahl, Florian Lach, Hiroyoshi Iwasaki, and Toshiki Sato

    Progress in the three-dimensional modeling of supernovae (SNe) prompts us to revisit the supernova remnant (SNR) phase. We continue our study of the imprint of a thermonuclear explosion on the SNR it produces, which we started with a delayed detonation model of a Chandrasekhar-mass white dwarf. Here we compare two different types of explosion models, each with two variants: two delayed detonation models

    更新日期:2021-01-12
  • ALMA and IRIS Observations of the Solar Chromosphere. II. Structure and Dynamics of Chromospheric Plages
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-12
    Georgios Chintzoglou, Bart De Pontieu, Juan Martínez-Sykora, Viggo Hansteen, Jaime de la Cruz Rodríguez, Mikolaj Szydlarski, Shahin Jafarzadeh, Sven Wedemeyer, Timothy S. Bastian, and Alberto Sainz Dalda

    We propose and employ a novel empirical method for determining chromospheric plage regions, which seems to better isolate a plage from its surrounding regions than other methods commonly used. We caution that isolating a plage from its immediate surroundings must be done with care in order to successfully mitigate statistical biases that, for instance, can impact quantitative comparisons between different

    更新日期:2021-01-12
  • Confrontation of Observation and Theory: High-frequency QPOs in X-Ray Binaries, Tidal Disruption Events, and Active Galactic Nuclei
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-12
    Krista Lynne Smith, Celia R. Tandon, and Robert V. Wagoner

    We compile observations of high-frequency quasi-periodic oscillations (QPOs) around black holes, both stellar and supermassive, and compare their positions in the parameter space of black hole mass, spin, and oscillation frequency. We find that supermassive black holes occupy a separate region of parameter space than stellar, and further, that QPOs seen around tidal disruption events rather than Seyfert-type

    更新日期:2021-01-12
  • Correlated X-Ray and Optical Variability in the O-type Supergiant ζ Puppis
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-12
    Joy S. Nichols, Yaël Nazé, David P. Huenemoerder, Anthony F. J. Moffat, Nathan A. Miller, Jennifer Lauer, Richard Ignace, Ken Gayley, Tahina Ramiaramanantsoa, Lidia Oskinova, Wolf-Rainer Hamann, Noel D. Richardson, Wayne L. Waldron, and Matthew Dahmer

    Analysis of the recent long exposure Chandra X-ray observation of the early-type O star ζ Pup shows clear variability with a period previously reported in optical photometric studies. These 813 ks of HETGS observations taken over a roughly one-year time span have two signals of periodic variability: (1) a high-significance period of 1.7820 ± 0.0008 day, and (2) a marginal detection of periodic behavior

    更新日期:2021-01-12
  • Modeling Kilonova Light Curves: Dependence on Nuclear Inputs
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-12
    Y. L. Zhu, K. A. Lund, J. Barnes, T. M. Sprouse, N. Vassh, G. C. McLaughlin, M. R. Mumpower, and R. Surman

    The mergers of binary neutron stars, as well as black hole–neutron star systems, are expected to produce an electromagnetic counterpart that can be analyzed to infer the element synthesis that occurred in these events. We investigate one source of uncertainties pertinent to lanthanide-rich outflows: the nuclear inputs to rapid neutron capture nucleosynthesis calculations. We begin by examining 32 different

    更新日期:2021-01-12
  • X-Ray Redshifts for Obscured AGN: A Case Study in the J1030 Deep Field
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-12
    Alessandro Peca, Cristian Vignali, Roberto Gilli, Marco Mignoli, Riccardo Nanni, Stefano Marchesi, Micol Bolzonella, Marcella Brusa, Nico Cappelluti, Andrea Comastri, Giorgio Lanzuisi, and Fabio Vito

    We present a procedure to constrain the redshifts of obscured ( ##IMG## [http://ej.iop.org/images/0004-637X/906/2/90/apjabc9c7ieqn1.gif] {${N}_{H}\gt {10}^{22}\,{\mathrm{cm}}^{-2}$} ) active galactic nuclei (AGN) based on low count statistics X-ray spectra, which can be adopted when photometric and/or spectroscopic redshifts are unavailable or difficult to obtain. We selected a sample of 54 obscured

    更新日期:2021-01-12
  • Systematic Study of AGN Clumpy Tori with Broadband X-Ray Spectroscopy: Updated Unified Picture of AGN Structure
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-12
    Shoji Ogawa, Yoshihiro Ueda, Atsushi Tanimoto, and Satoshi Yamada

    We present the results of a systematic, broadband X-ray spectral analysis of nearby active galactic nuclei (AGNs) with the X-ray clumpy torus model (XCLUMPY). By adding 16 AGNs newly analyzed in this paper, we study a total of 28 AGNs, including unabsorbed and absorbed AGNs taken from Ichikawa et al. and García-Bernete et al. This is the largest sample whose X-ray and infrared spectra are analyzed

    更新日期:2021-01-12
  • NuSTAR Observations of Abell 2163: Constraints on Non-thermal Emission
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-12
    Randall A. Rojas Bolivar, Daniel R. Wik, Simona Giacintucci, Fabio Gastaldello, Allan Hornstrup, Niels-Jorgen Westergaard, and Grzegorz Madejski

    Since the first non-thermal reports of inverse Compton (IC) emission from the intracluster medium (ICM) of galaxy clusters at hard X-ray energies, we have yet to unambiguously confirm IC emission in observations with newer facilities. RXTE detected IC emission in one of the hottest known clusters, Abell 2163 (A2163), a massive merging cluster with a giant radio halo—the presumed source of relativistic

    更新日期:2021-01-12
  • Metamorphosis of a Dwarf Halo Density Profile under Dark Matter Decay
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-12
    Jianxiong Chen and M.-C. Chu

    We have studied the density profile of a dwarf halo in the decaying dark matter (DDM) cosmology, using a new algorithm that resolves halo density profiles down to the innermost 700 pc robustly with high efficiency. Following Schwarzschild’s orbit-based method, we have also developed a simplified model to calculate the DDM halo density profiles, which agree remarkably well with those from N -body simulations

    更新日期:2021-01-12
  • A Two-zone Photohadronic Interpretation of the EHBL-like Behavior of the 2016 Multi-TeV Flares of 1ES 1959+650
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-12
    Sarira Sahu, Carlos E. López Fortín, Luis H. Castañeda Hernández, and Subhash Rajpoot

    The high-energy-peaked blazar 1ES 1959+650 is a well-known and well-studied nearby blazar that has undergone several episodes of multi-TeV flaring. In 2002 for the first time an orphan TeV flare was observed from this blazar. During a multiwavelength campaign from 2016 April 29 to November 21, MAGIC telescopes observed multi-TeV flarings during the nights of 2016 June 13 and 14 and July 1 when the

    更新日期:2021-01-12
  • Cosmic Inference: Constraining Parameters with Observations and a Highly Limited Number of Simulations
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    Timur Takhtaganov, Zarija Lukić, Juliane Müller, and Dmitriy Morozov

    Cosmological probes pose an inverse problem where the measurement result is obtained through observations, and the objective is to infer values of model parameters that characterize the underlying physical system—our universe, from these observations and theoretical forward-modeling. The only way to accurately forward-model physical behavior on small scales is via expensive numerical simulations, which

    更新日期:2021-01-12
  • Lorentz–Lorenz Coefficient of Ice Molecules of Astrophysical Interest: N 2 , CO 2 , NH 3 , CH 4 , CH 3 OH, C 2 H 4 , and C 2 H 6
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    M. Domingo, R. Luna, M. Á. Satorre, C. Santonja, and C. Millán

    This work calculates the Lorentz–Lorenz coefficient with the refractive index and density values of various molecules in their solid phase measured in our laboratory under astrophysical conditions. This was completed for a range of temperatures from 13 K to close to the sublimation temperature for each molecule. The studied molecules were N 2 , CO 2 , NH 3 , CH 4 , CH 3 OH, C 2 H 4 , and C 2 H 6 .

    更新日期:2021-01-12
  • Multiple Stellar Populations along the Red Horizontal Branch and Red Clump of Globular Clusters
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    E. Dondoglio, A. P. Milone, E. P. Lagioia, A. F. Marino, M. Tailo, G. Cordoni, S. Jang, and M. Carlos

    We exploit multiband Hubble Space Telescope photometry to investigate multiple populations (MPs) along the red horizontal branches (HBs) and red clumps of 14 metal-rich globular clusters (GCs), including 12 Milky Way GCs and the Magellanic Cloud GCs NGC 1978 and NGC 416. Based on appropriate two-color diagrams, we find that the fraction of first-generation (1G) stars in Galactic GCs correlates with

    更新日期:2021-01-12
  • The CARMA-NRO Orion Survey: Filament Formation via Collision-induced Magnetic Reconnection—the Stick in Orion A
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    Shuo Kong, Volker Ossenkopf-Okada, Héctor G. Arce, John Bally, Álvaro Sánchez-Monge, Peregrine McGehee, Sümeyye Suri, Ralf S. Klessen, John M. Carpenter, Dariusz C. Lis, Fumitaka Nakamura, Peter Schilke, Rowan J. Smith, Steve Mairs, Alyssa Goodman, and María José Maureira

    A unique filament is identified in the Herschel maps of the Orion A giant molecular cloud. The filament, which we name the Stick, is ruler-straight and at an early evolutionary stage. Transverse position–velocity diagrams show two velocity components closing in on the Stick. The filament shows consecutive rings/forks in C 18 O (1−0) channel maps, which is reminiscent of structures generated by magnetic

    更新日期:2021-01-12
  • The Formation and Eruption of a Sigmoidal Filament Driven by Rotating Network Magnetic Fields
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    Jun Dai, Haisheng Ji, Leping Li, Jun Zhang, and Huadong Chen

    We present the formation and eruption of a sigmoidal filament driven by rotating network magnetic fields (RNFs) near the center of the solar disk, which was observed by the 1 m aperture New Vacuum Solar Telescope at the Fuxian Solar Observatory on 2018 July 12. Counterclockwise RNFs twist two small-scale filaments at their northeastern foot-point region, giving a rotation of nearly 200° within about

    更新日期:2021-01-12
  • New Horizons Observations of the Cosmic Optical Background
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    Tod R. Lauer, Marc Postman, Harold A. Weaver, John R. Spencer, S. Alan Stern, Marc W. Buie, Daniel D. Durda, Carey M. Lisse, A. R. Poppe, Richard P. Binzel, Daniel T. Britt, Bonnie J. Buratti, Andrew F. Cheng, W. M. Grundy, Mihaly Horányi, J. J. Kavelaars, Ivan R. Linscott, William B. McKinnon, Jeffrey M. Moore, J. I. Núñez, Catherine B. Olkin, Joel W. Parker, Simon B. Porter, Dennis C. Reuter, Stuart

    We used existing data from the New Horizons Long-range Reconnaissance Imager (LORRI) to measure the optical-band(0.4 ≲ λ ≲ 0.9 μ m) sky brightness within seven high–Galactic latitude fields. The average raw level measured while New Horizons was 42–45 au from the Sun is 33.2 ± 0.5 nW m −2 sr −1 . This is ∼10× as dark as the darkest sky accessible to the Hubble Space Telescope, highlighting the utility

    更新日期:2021-01-12
  • Statistical Properties of Superflares on Solar-type Stars: Results Using All of the Kepler Primary Mission Data
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    Soshi Okamoto, Yuta Notsu, Hiroyuki Maehara, Kosuke Namekata, Satoshi Honda, Kai Ikuta, Daisaku Nogami, and Kazunari Shibata

    We report the latest statistical analyses of superflares on solar-type (G-type main-sequence; effective temperature is 5100–6000 K) stars using all of the Kepler primary mission data and Gaia Data Release 2 catalog. We updated the flare detection method from our previous studies by using a high-pass filter to remove rotational variations caused by starspots. We also examined the sample biases on the

    更新日期:2021-01-12
  • Observational Constraints on the Physical Properties of Interstellar Dust in the Post-Planck Era
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    Brandon S. Hensley and B. T. Draine

    We present a synthesis of the astronomical observations constraining the wavelength-dependent extinction, emission, and polarization from interstellar dust from UV to microwave wavelengths on diffuse Galactic sight lines. Representative solid-phase abundances for those sight lines are also derived. Given the sensitive new observations of polarized dust emission provided by the Planck satellite, we

    更新日期:2021-01-12
  • Does the Disk in the Hard State of XTE J1752–223 Extend to the Innermost Stable Circular Orbit?
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    Andrzej A. Zdziarski, Barbara De Marco, Michał Szanecki, Andrzej Niedźwiecki, and Alex Markowitz

    The accreting black hole binary XTE J1752–223 was observed in a stable hard state for 25 days by the Rossi X-ray Timing Explorer (RXTE), yielding a 3–140 keV spectrum of unprecedented statistical quality. Its published model required a single-Comptonization spectrum reflecting from a disk close to the innermost stable circular orbit. We studied that model as well as a number of other single-Comptonization

    更新日期:2021-01-12
  • Waves and Turbulence in the Very Local Interstellar Medium: From Macroscales to Microscales
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    Federico Fraternale and Nikolai V. Pogorelov

    Voyager 1 ( V1 ) has been exploring the heliospheric boundary layer in the very local interstellar medium (VLISM) since 2012 August. The measurements revealed a spectrum of fluctuations over a vast range of space and timescales, but the nature of these fluctuations continues to be an intriguing question. Numerous manifestations of turbulence cannot be explained using a single phenomenology. Weak shocks

    更新日期:2021-01-12
  • Torsional Alfvén Wave Cascade and Shocks Evolving in Solar Jets
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    S. Vasheghani Farahani, S. M. Hejazi, and M. R. Boroomand

    The aim of this study is to model the nature of nonlinear torsional magnetohydrodynamic waves propagating in solar jets as they are elevated to the outer solar atmosphere. The contribution of sequential processes to the transfer of energy is taken under consideration: the nonlinear cascade and shock formation. Thus a straight magnetic cylinder embedded in a plasma with an initial magnetic field and

    更新日期:2021-01-12
  • Properties of Galaxies in Cosmic Filaments around the Virgo Cluster
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    Youngdae Lee, Suk Kim, Soo-Chang Rey, and Jiwon Chung

    We present the properties of galaxies in filaments around the Virgo cluster with respect to their vertical distance from the filament spine using the NASA–Sloan Atlas catalog. The filaments are mainly composed of low-mass, blue dwarf galaxies. We observe that the g − r color of galaxies becomes blue and stellar mass decreases with increasing vertical filament distance. The galaxies were divided into

    更新日期:2021-01-12
  • Escaping Outflows from Disintegrating Exoplanets: Day-side versus Night-side Escape
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    Wanying Kang, Feng Ding, Robin Wordsworth, and Sara Seager

    Ultrahot disintegrating exoplanets have been detected with tails trailing behind and/or shooting ahead of them. These tails are believed to be made of dust that are formed out of the supersonic escaping flow that emanated from the permanent day side. Conserving angular momentum, this day-side escape flux would lead the planet in orbit. In order to explain the trailing tails in observation, radiation

    更新日期:2021-01-12
  • On the Occurrence of Type IV Solar Radio Bursts in Solar Cycle 24 and Their Association with Coronal Mass Ejections
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    Anshu Kumari, D. E. Morosan, and E. K. J. Kilpua

    Solar activities, in particular coronal mass ejections (CMEs), are often accompanied by bursts of radiation at meter wavelengths. Some of these bursts have a long duration and extend over a wide frequency band, namely, type IV radio bursts. However, the association of type IV bursts with CMEs is still not well understood. In this article, we perform the first statistical study of type IV solar radio

    更新日期:2021-01-12
  • Dust Temperature of Compact Star-forming Galaxies at z ∼ 1–3 in 3D-HST/CANDELS
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    Zuyi Chen, Guanwen Fang, Zesen Lin, Hongxin Zhang, Guangwen Chen, and Xu Kong

    Recent simulation studies suggest that the compaction of star-forming galaxies (SFGs) at high redshift might be a critical process, during which the central bulge is being rapidly built, followed by quenching of the star formation. To explore dust properties of SFGs with compact morphology, we investigate the dependence of dust temperature, T dust , on their size and star formation activity, using

    更新日期:2021-01-12
  • A Two-moment Radiation Hydrodynamics Scheme Applicable to Simulations of Planet Formation in Circumstellar Disks
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-11
    Julio David Melon Fuksman, Hubert Klahr, Mario Flock, and Andrea Mignone

    We present a numerical code for radiation hydrodynamics designed as a module for the freely available PLUTO code. We adopt a gray approximation and include radiative transfer following a two-moment approach by imposing the M1 closure to the radiation fields. This closure allows for a description of radiative transport in both the diffusion and free-streaming limits, and is able to describe highly anisotropic

    更新日期:2021-01-12
  • A Two-zone Blazar Radiation Model for “Orphan” Neutrino Flares
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-06
    Rui Xue, Ruo-Yu Liu, Ze-Rui Wang, Nan Ding, and Xiang-Yu Wang

    In this work, we investigate the 2014–2015 neutrino flare associated with the blazar TXS 0506+056 and a recently discovered muon neutrino event IceCube-200107A in spatial coincidence with the blazar 4FGL J0955.1+3551, under the framework of a two-zone radiation model of blazars where an inner/outer blob close to/far from the supermassive black hole is invoked. An interesting feature that the two sources

    更新日期:2021-01-06
  • Evolutionary Models for the Remnant of the Merger of Two Carbon-Oxygen Core White Dwarfs
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-06
    Josiah Schwab

    We construct evolutionary models of the remnant of the merger of two carbon-oxygen (CO) core white dwarfs (WDs). With total masses in the range 1–2 M ⊙ , these remnants may either leave behind a single massive WD or undergo a merger-induced collapse to a neutron star (NS). On the way to their final fate, these objects generally experience a ∼10 kyr luminous giant phase, which may be extended if sufficient

    更新日期:2021-01-06
  • Differential Modeling Systematics across the HR Diagram from Asteroseismic Surface Corrections
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-06
    J. M. Joel Ong, Sarbani Basu, and Jean M. McKeever

    Localized modeling error in the near-surface layers of evolutionary stellar models causes the frequencies of their normal modes of oscillation to differ from those of actual stars with matching interior structures. These frequency differences are referred to as the asteroseismic surface term. Global stellar properties estimated via detailed constraints on individual mode frequencies have previously

    更新日期:2021-01-06
  • Accretion of Gas Giants Constrained by the Tidal Barrier
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-06
    Ya-Ping Li, Yi-Xian Chen, Douglas N. C. Lin, and Xiaojia Zhang

    After protoplanets have acquired sufficient mass to open partial gaps in their natal protostellar disks, residual gas continues to diffuse onto horseshoe streamlines under the effect of viscous dissipation, and to meander in and out of the planets’ Hill sphere. Within the Hill sphere, the horseshoe streamlines intercept gas flow in circumplanetary disks. The host star’s tidal perturbation induces a

    更新日期:2021-01-06
  • Intergalactic Medium Dispersion Measures of Fast Radio Bursts Estimated from IllustrisTNG Simulation and Their Cosmological Applications
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-06
    Z. J. Zhang, K. Yan, C. M. Li, G. Q. Zhang, and F. Y. Wang

    Fast radio bursts (FRBs) are millisecond-duration radio transients and can be used as a cosmological probe. However, the dispersion measure (DM) contributed by the intergalactic medium (IGM) is hard to distinguish from other components. In this paper, we use the IllustrisTNG simulation to realistically estimate DM IGM up to z ∼ 9. We find ##IMG## [http://ej.iop.org/images/0004-637X/906/1/49/apjabceb9ieqn1

    更新日期:2021-01-06
  • Robotic Reverberation Mapping of the Southern Seyfert NGC 3783
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-06
    Misty C. Bentz, Rachel Street, Christopher A. Onken, and Monica Valluri

    We present spectroscopic and photometric monitoring of NGC 3783 conducted throughout the first half of 2020. Time delays between the continuum variations and the response of the broad optical emission lines were clearly detected, and we report reverberation measurements for H β , He ii λ 4686, H γ , and H δ . From the time delay in the broad H β emission line and the line width in the variable portion

    更新日期:2021-01-06
  • Three-dimensional Distribution of the Interstellar Dust in the Milky Way
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-05
    H.-L. Guo, B.-Q. Chen, H.-B. Yuan, Y. Huang, D.-Z Liu, Y. Yang, X.-Y. Li, W.-X. Sun, and X.-W. Liu

    We present a three-dimensional (3D) extinction map of the southern sky. The map covers the SkyMapper Southern Survey (SMSS) area of ∼14,000 deg 2 and has spatial resolutions between 6.′9 and 27′. Based on the multi-band photometry of SMSS, the Two Micron All Sky Survey, the Wide-Field Infrared Survey Explorer Survey, and the Gaia mission, we have estimated values of the r -band extinction for ∼19 million

    更新日期:2021-01-06
  • Black Hole Accretion Correlates with Star Formation Rate and Star Formation Efficiency in Nearby Luminous Type 1 Active Galaxies
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-05
    Ming-Yang Zhuang, Luis C. Ho, and Jinyi Shangguan

    We investigate the relationship between black hole accretion and star formation in a sample of 453 z ≈ 0.3 type 1 active galactic nuclei (AGNs). We use available CO observations to demonstrate that the combination of nebular dust extinction and metallicity provides reliable estimates of the molecular gas mass even for the host galaxies of type 1 AGNs. Consistent with other similar but significantly

    更新日期:2021-01-06
  • The SAMI Galaxy Survey: Stellar Populations of Passive Spiral Galaxies in Different Environments
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-05
    Mina Pak, Sree Oh, Joon Hyeop Lee, Nicholas Scott, Rory Smith, Jesse van de Sande, Scott M. Croom, Francesco D’Eugenio, Kenji Bekki, Sarah Brough, Caroline Foster, Tania M. Barone, Katarina Kraljic, Hyunjin Jeong, Joss Bland-Hawthorn, Julia J. Bryant, Michael Goodwin, Jon Lawrence, Matt S. Owers, and Samuel N. Richards

    We investigate the stellar populations of passive spiral galaxies as a function of mass and environment, using integral field spectroscopy data from the Sydney-AAO Multi-object Integral field spectrograph Galaxy Survey. Our sample consists of 52 cluster passive spirals and 18 group/field passive spirals, as well as a set of S0s used as a control sample. The age and [Z/H] estimated by measuring Lick

    更新日期:2021-01-06
  • Linking Soft Excess in Ultraluminous X-Ray Sources with Optically Thick Wind Driven by Supercritical Accretion
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-05
    Yanli Qiu and Hua Feng

    Supercritical accretion onto compact objects may drive massive winds that are nearly spherical, optically thick, and Eddington limited. Blackbody emission from the photosphere is the direct observational signature of the wind. Here we investigate whether or not it can explain the soft emission component seen in the energy spectra of ultraluminous X-ray sources (ULXs). Based on high-quality XMM-Newton

    更新日期:2021-01-06
  • Silicon and Hydrogen Chemistry under Laboratory Conditions Mimicking the Atmosphere of Evolved Stars
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-05
    Mario Accolla, Gonzalo Santoro, Pablo Merino, Lidia Martínez, Guillermo Tajuelo-Castilla, Luis Vázquez, Jesús M. Sobrado, Marcelino Agúndez, Miguel Jiménez-Redondo, Víctor J. Herrero, Isabel Tanarro, José Cernicharo, and José Ángel Martín-Gago

    Silicon is present in interstellar dust grains, meteorites and asteroids, and to date 13 silicon-bearing molecules have been detected in the gas phase toward late-type stars or molecular clouds, including silane and silane derivatives. In this work, we have experimentally studied the interaction between atomic silicon and hydrogen under physical conditions mimicking those in the atmosphere of evolved

    更新日期:2021-01-06
  • The Impact of Kinetic Neutrals on the Heliotail
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-05
    A. T. Michael, M. Opher, G. Tóth, V. Tenishev, and J. F. Drake

    The shape of the heliosphere is thought to resemble a long, comet tail, however, recently it has been suggested that the heliosphere is tailless with a two-lobe structure. The latter study was done with a three-dimensional (3D) magnetohydrodynamic code, which treats the ionized and neutral hydrogen atoms as fluids. Previous studies that described the neutrals kinetically claim that this removes the

    更新日期:2021-01-06
  • Disks as Inhomogeneous, Anisotropic Gaussian Random Fields
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-05
    Daeyoung Lee and Charles F. Gammie

    We model astrophysical disk surface brightness fluctuations as an inhomogeneous, anisotropic, time-dependent Gaussian random field. The field locally obeys the stochastic partial differential equation of a Matérn field, which has a power spectrum that is flat at large scales and falls off as a power law at small scales. We provide a series of pedagogical examples and along the way provide a convenient

    更新日期:2021-01-06
  • CMB Cold Spot in the Planck Light
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-05
    M. Farhang and S. M. S. Movahed

    The Cold Spot, with an unusually cold region surrounded by a hot ring, is a statistically significant anomaly in the cosmic microwave background (CMB) sky. In this work we assess whether different sets of multiple subvoids based on the 2dF-VST ATLAS Cold Spot galaxy redshift survey or a collapsing cosmic texture could have produced such an anomaly through a simultaneous search for their gravitational

    更新日期:2021-01-06
  • Chandra Observations of Abell 2261 Brightest Cluster Galaxy, a Candidate Host to a Recoiling Black Hole
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-05
    Kayhan Gültekin, Sarah Burke-Spolaor, Tod R. Lauer, T. Joseph W. Lazio, Leonidas A. Moustakas, Patrick Ogle, and Marc Postman

    We use Chandra X-ray observations to look for evidence of a recoiling black hole from the brightest cluster galaxy in Abell 2261 (A2261-BCG). A2261-BCG is a strong candidate for a recoiling black hole because of its large, flat stellar core, revealed by Hubble Space Telescope imaging observations. We took 100 ks observations with Chandra and combined it with 35 ks of archival observations to look for

    更新日期:2021-01-06
  • Structure and Evolution of an Inter–Active Region Large-scale Magnetic Flux Rope
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-05
    Aiying Duan, Chaowei Jiang, Peng Zou, Xueshang Feng, and Jun Cui

    Magnetic flux rope (MFR) has been recognized as the key magnetic configuration of solar eruptions. While pre-eruption MFRs within the core of solar active regions (ARs) have been widely studied, those existing between two ARs, i.e., the intermediate ones in weak-field regions, were rarely studied. There are also major eruptions that occurred in such intermediate regions and study of the MFR there will

    更新日期:2021-01-06
  • Metal-THINGS: On the Metallicity and Ionization of ULX Sources in NGC 925
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-05
    Maritza A. Lara-López, Igor A. Zinchenko, Leonid S. Pilyugin, Madusha L. P. Gunawardhana, Omar López-Cruz, Shane P. O’ Sullivan, Anna Feltre, Margarita Rosado, Mónica Sánchez-Cruces, Jacopo Chevallard, Maria Emilia De Rossi, Sami Dib, Jacopo Fritz, Isaura Fuentes-Carrera, Luis E. Garduño, and Eduardo Ibar

    We present an analysis of the optical properties of three Ultra Luminous X-ray (ULX) sources identified in NGC 925. We use Integral field unit data from the George Mitchel spectrograph in the context of the Metal-THINGS survey. The optical properties for ULX-1 and ULX-3 are presented, while the spaxel associated with ULX-2 had a low S/N, which prevented its analysis. We also report the kinematics and

    更新日期:2021-01-06
  • A New Method to Estimate Halo CME Mass Using Synthetic CMEs Based on a Full Ice Cream Cone Model
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-05
    Hyeonock Na, Yong-Jae Moon, Jin-Yi Lee, and Il-Hyun Cho

    In this study, we suggest a new method to estimate the mass of a halo coronal mass ejection (CME) using synthetic CMEs. For this, we generate synthetic CMEs based on two assumptions: (1) the CME structure is a full ice cream cone, and (2) the CME electron number density follows a power-law distribution ( ρ cme = ρ 0 r − n ). The power-law exponent n is obtained by minimizing the rms error between the

    更新日期:2021-01-06
  • Flare Activity and Magnetic Feature Analysis of the Flare Stars. II. Subgiant Branch
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-05
    Hadis Goodarzi, Ahmad Mehrabi, Habib G. Khosroshahi, and Han He

    We present an investigation of the magnetic activity and flare characteristics of the subgiant stars mostly from F and G spectral types and compare the results with the main-sequence (MS) stars. The light curve of 352 stars on the subgiant branch (SGB) from the Kepler mission is analyzed in order to infer stability, relative coverage, and contrast of the magnetic structures and also flare properties

    更新日期:2021-01-06
  • A VLBA Survey of Radio Stars in the Orion Nebula Cluster. I. The Nonthermal Radio Population
    Astrophys. J.  (IF 5.745) Pub Date : 2021-01-04
    Jan Forbrich, Sergio A. Dzib, Mark J. Reid, and Karl M. Menten

    We present first results of a four-epoch VLBA survey for nonthermal emission toward all 556 compact radio sources previously identified in a deep VLA survey of the Orion Nebula Cluster (ONC). We identify VLBA counterparts toward an unprecedented 123 sources. Of these, 41 do not have X-ray counterparts, of which 34 also do not display near-infrared counterparts. Since these cannot be explained by extragalactic

    更新日期:2021-01-06
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