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Chandra and HST Studies of Six Millisecond Pulsars in the Globular Cluster M13 Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-19 Jiaqi Zhao; Yue Zhao; Craig O Heinke
We analyse 55 ks of Chandra X-ray observations of the Galactic globular cluster M13. Using the latest radio timing positions of six known millisecond pulsars (MSPs) in M13 from Wang et al. (2020), we detect confident X-ray counterparts to five of the six MSPs at X-ray luminosities of LX(0.3-8 keV)∼3 × 1030 − 1031 erg s−1, including the newly discovered PSR J1641 + 3627F. There are limited X-ray counts
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Age–metallicity dependent stellar kinematics of the Milky Way disc from LAMOST and Gaia Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-19 Wu Y, Xiang M, Chen Y, et al.
ABSTRACTWe investigate the stellar kinematics of the Galactic disc in 7 < R < 13 kpc using a sample of 118 945 red giant branch (RGB) stars from the Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) and Gaia. We characterize the median, dispersion and skewness of the distributions of the three-dimensional stellar velocities, actions and orbital parameters across the age–metallicity
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LYRA I: Simulating the multi-phase ISM of a dwarf galaxy with variable energy supernovae from individual stars Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-19 Thales A Gutcke; Rüdiger Pakmor; Thorsten Naab; Volker Springel
We introduce the LYRA project, a new high resolution galaxy formation model built within the framework of the cosmological hydro-dynamical moving mesh code arepo. The model resolves the multi-phase interstellar medium down to 10 K. It forms individual stars sampled from the initial mass function (IMF), and tracks their lifetimes and death pathways individually. Single supernova (SN) blast waves with
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Improved early warning of compact binary mergers using higher modes of gravitational radiation: A population study Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-19 Mukesh Kumar Singh; Shasvath J Kapadia; Md Arif Shaikh; Deep Chatterjee; Parameswaran Ajith
A gravitational-wave (GW) early-warning of a compact-binary coalescence event, with a sufficiently tight localisation skymap, would allow telescopes to point in the direction of the potential electromagnetic counterpart before its onset. Use of higher-modes of gravitational radiation, in addition to the dominant mode typically used in templated real-time searches, was recently shown to produce significant
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Rotating vector model for magnetars Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-19 H Tong; P F Wang; H G Wang; Z Yan
The modification of the rotating vector model in the case of magnetars are calculated. Magnetars may have twisted magnetic field compared with normal pulsars. The polarization position angle of magnetars will change in the case of a twisted magnetic field. For a twisted dipole field, we found that the position angle will change both vertically and horizontally. During the untwisting process of the
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Setting the stage: structures from Gaussian random fields Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-16 Sawala T, Jenkins A, McAlpine S, et al.
ABSTRACTWe study structure formation in a set of cosmological simulations to uncover the scales in the initial density field that gave rise to the formation of present-day structures. Our simulations share a common primordial power spectrum (here Λ cold dark matter, ΛCDM), but the introduction of hierarchical variations of the phase information allows us to systematically study the scales that determine
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The effect of magnetic fields on properties of the circumgalactic medium Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-06 van de Voort F, Bieri R, Pakmor R, et al.
ABSTRACTWe study the effect of magnetic fields on a simulated galaxy and its surrounding gaseous halo, or circumgalactic medium (CGM), within cosmological ‘zoom-in’ simulations of a Milky Way-mass galaxy as part of the Simulating the Universe with Refined Galaxy Environments (SURGE) project. We use three different galaxy formation models, each with and without magnetic fields, and include additional
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Photometric analysis of three totally eclipsing W UMa stars with increasing periods: TYC 3700-1384-1, V1511 Her, and V1179 Her Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-24 Broens E.
ABSTRACTThe first multicolour light-curve models and period studies for the totally eclipsing W UMa stars TYC 3700-1384-1, V1511 Her, and V1179 Her are presented. All three stars are A-subtype W UMa stars of spectral type F. The light-curve solutions show that TYC 3700-1384-1 has a moderately low mass ratio of q = 0.182 ± 0.001 and a degree of overcontact of $f = 49 {{\ \rm per\ cent}}$. For V1179
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O vi traces photoionized streams with collisionally ionized boundaries in cosmological simulations of z ∼ 1 massive galaxies Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-24 Strawn C, Roca-Fàbrega S, Mandelker N, et al.
ABSTRACTWe analyse the distribution and origin of O vi in the Circumgalactic Medium (CGM) of dark-matter haloes of ∼1012 M⊙ at z ∼ 1 in the VELA cosmological zoom-in simulations. We find that the O vi in the inflowing cold streams is primarily photoionized, while in the bulk volume it is primarily collisionally ionized. The photoionized component dominates the observed column density at large impact
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An accurate reconstruction of CMB E-mode signal over large angular scales using prior information of CMB covariance matrix in ILC algorithm Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-23 Purkayastha U, Sudevan V, Saha R.
ABSTRACTRecently, the internal-linear-combination (ILC) method was investigated extensively in the context of reconstruction of Cosmic Microwave Background (CMB) temperature anisotropy signal using observations obtained by WMAP and Planck satellite missions. In this article, we, for the first time, apply the ILC method to reconstruct the large-scale CMB E mode polarization signal, which could probe
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On ancient solar-type stars – II Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-23 Fuhrmann K, Chini R.
ABSTRACTWe report on the progress of our survey on ancient solar-type stars down to main-sequence effective temperatures Teff ≥ 5300 K and within 42 pc of the Sun. High signal-to-noise, high-resolution spectroscopy is presented for a second major subset of the Population II (τ ≥ 12 Gyr) and the intermediate-disc stars (τ ≃ 10 Gyr) within that volume. In conjunction with updates and the analyses of
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Simulations of radiation-driven winds from Keplerian discs Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-23 Raychaudhuri S, Vyas M, Chattopadhyay I.
ABSTRACTWe study the ejection of winds from thin accretion discs around stellar mass black holes and the time evolution of these winds in the presence of radiation field generated by the accretion disc. Winds are produced by radiation, thermal pressure, and the centrifugal force of the disc. The winds are found to be mildly relativistic, with speeds reaching up to terminal speeds of 0.1 for accretion
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The magnetic field in the dense photodissociation region of DR 21 Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-21 Koley A, Roy N, Menten K, et al.
ABSTRACTMeasuring interstellar magnetic fields is extremely important for understanding their role in different evolutionary stages of interstellar clouds and star formation. However, detecting the weak field is observationally challenging. We present measurements of the Zeeman effect in the 1665 and 1667 MHz (18 cm) lines of the hydroxyl radical (OH) lines towards the dense photodissociation region
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Mildly relativistic magnetized shocks in electron–ion plasmas – I. Electromagnetic shock structure Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-21 Ligorini A, Niemiec J, Kobzar O, et al.
ABSTRACTMildly relativistic shocks in magnetized electron–ion plasmas are investigated with 2D kinetic particle-in-cell simulations of unprecedentedly high resolution and large scale for conditions that may be found at internal shocks in blazar cores. Ion-scale effects cause corrugations along the shock surface whose properties somewhat depend on the configuration of the mean perpendicular magnetic
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The effect of environment on Type Ia supernovae in the Dark Energy Survey three-year cosmological sample Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-21 Kelsey L, Sullivan M, Smith M, et al.
ABSTRACTAnalyses of Type Ia supernovae (SNe Ia) have found puzzling correlations between their standardized luminosities and host galaxy properties: SNe Ia in high-mass, passive hosts appear brighter than those in lower mass, star-forming hosts. We examine the host galaxies of SNe Ia in the Dark Energy Survey 3-yr spectroscopically confirmed cosmological sample, obtaining photometry in a series of
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The time-scales probed by star formation rate indicators for realistic, bursty star formation histories from the FIRE simulations Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-17 Flores Velázquez J, Gurvich A, Faucher-Giguère C, et al.
ABSTRACTUnderstanding the rate at which stars form is central to studies of galaxy formation. Observationally, the star formation rates (SFRs) of galaxies are measured using the luminosity in different frequency bands, often under the assumption of a time-steady SFR in the recent past. We use star formation histories (SFHs) extracted from cosmological simulations of star-forming galaxies from the FIRE
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Stability constrained characterization of multiplanet systems Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-17 Tamayo D, Gilbertson C, Foreman-Mackey D.
ABSTRACTMany discovered multiplanet systems are tightly packed. This implies that wide parameter ranges in masses and orbital elements can be dynamically unstable and ruled out. We present a case study of Kepler-23, a compact three-planet system where constraints from stability, transit timing variations (TTVs), and transit durations can be directly compared. We find that in this tightly packed system
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The ALMaQUEST Survey – V. The non-universality of kpc-scale star formation relations and the factors that drive them Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-12 Ellison S, Lin L, Thorp M, et al.
ABSTRACTUsing a sample of ∼15 000 kpc-scale star-forming spaxels in 28 galaxies drawn from the ALMA-MaNGA QUEnching and STar formation (ALMaQUEST) survey, we investigate the galaxy-to-galaxy variation of the ‘resolved’ Schmidt–Kennicutt relation (rSK; $\Sigma _{\rm H_2}$–ΣSFR), the ‘resolved’ star-forming main sequence (rSFMS; Σ⋆–ΣSFR), and the ‘resolved’ molecular gas main sequence (rMGMS; Σ⋆–$\Sigma
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Erratum: Short-term stability of particles in the WD J0914+1914 white dwarf planetary system Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-18 Zotos E, Veras D, Saeed T, et al.
errata, addendaplanets and satellites: dynamical evolution and stabilityplanet–star interactionsprotoplanetary discs
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Planet Hunters TESS II: findings from the first two years of TESS Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-08 Eisner N, Barragán O, Lintott C, et al.
ABSTRACTWe present the results from the first two years of the Planet Hunters TESS (PHT) citizen science project, which identifies planet candidates in the TESS (Transiting Exoplanet Survey Satellite) data by engaging members of the general public. Over 22 000 citizen scientists from around the world visually inspected the first 26 sectors of TESS data in order to help identify transit-like signals
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Magnetogenesis around the first galaxies: the impact of different field seeding processes on galaxy formation Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-16 Enrico Garaldi; Rüdiger Pakmor; Volker Springel
We study the evolution of magnetic fields generated by charge segregation ahead of ionization fronts during the Epoch of Reionization, and their effects on galaxy formation. We compare this magnetic seeding process with the Biermann battery, injection from supernovae, and an imposed seed field at redshift z ≳ 127. Using a suite of self-consistent cosmological and zoom-in simulations based on the Auriga
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hmcode-2020: Improved modelling of non-linear cosmological power spectra with baryonic feedback Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-16 A J Mead; S Brieden; T Tröster; C Heymans
We present an updated version of the hmcode augmented halo model that can be used to make accurate predictions of the non-linear matter power spectrum over a wide range of cosmologies. Major improvements include modelling of BAO damping in the power spectrum and an updated treatment of massive neutrinos. We fit our model to simulated power spectra and show that we can match the results with an RMS
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Can the Local Bubble explain the radio background? Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-16 Martin G H Krause; Martin J Hardcastle
The ARCADE 2 balloon bolometer along with a number of other instruments have detected what appears to be a radio synchrotron background at frequencies below about 3 GHz. Neither extragalactic radio sources nor diffuse Galactic emission can currently account for this finding. We use the locally measured Cosmic ray electron population, demodulated for effects of the Solar wind, and other observational
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Retraction Notice: Revised instellation patterns for close-in exoplanets Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-14 Sadh M.
MNRAS is retracting the following article
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Red noise and pulsations in evolved massive stars Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-16 Yaël Nazé; Gregor Rauw; Eric Gosset
We examine high-cadence space photometry taken by the Transiting Exoplanet Survey Satellite (TESS) of a sample of evolved massive stars (26 Wolf-Rayet stars and 8 Luminous Blue Variables or candidate LBVs). To avoid confusion problems, only stars without bright Gaia neighbours and without evidence of bound companions are considered. This leads to a clean sample, whose variability properties should
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3D magnetised jet break-out from neutron-star binary merger ejecta: afterglow emission from the jet and the ejecta Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-16 Antonios Nathanail; Ramandeep Gill; Oliver Porth; Christian M Fromm; Luciano Rezzolla
We perform three-dimensional (3D) general-relativistic magnetohydrodynamic simulations to model the jet break-out from the ejecta expected to be produced in a binary neutron-star merger. The structure of the relativistic outflow from the 3D simulation confirms our previous results from 2D simulations, namely, that a relativistic magnetized outflow breaking out from the merger ejecta exhibits a hollow
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Comparing galaxy formation in the L-GALAXIES semi-analytical model and the IllustrisTNG simulations Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-16 Mohammadreza Ayromlou; Dylan Nelson; Robert M Yates; Guinevere Kauffmann; Malin Renneby; Simon D M White
We perform a comparison, object-by-object and statistically, between the Munich semi-analytical model, L-Galaxies, and the IllustrisTNG hydrodynamical simulations. By running L-Galaxies on the IllustrisTNG dark matter-only merger trees, we identify the same galaxies in the two models. This allows us to compare the stellar mass, star formation rate and gas content of galaxies, as well as the baryonic
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Periastron shift of compact stellar orbits from general relativistic and tidal distortion effects near Sgr A* Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-16 P C Lalremruati; Sanjeev Kalita
The Galactic Centre (Sgr A*), hosting a supermassive black hole carries sufficient potential for testing gravitational theories. Existing astrometric facilities on Very Large Telescope (VLT) and the Keck Telescope have enabled astronomers to study stellar orbits near Sgr A* and perform new astronomical tests of gravitational theories. These observations have provided strong field tests of gravity (φ/c2
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Magnetic fields in the Milky Way from pulsar observations: effect of the correlation between thermal electrons and magnetic fields Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-16 Amit Seta; Christoph Federrath
Pulsars can act as an excellent probe of the Milky Way magnetic field. The average strength of the Galactic magnetic field component parallel to the line of sight can be estimated as 〈B∥〉 = 1.232 RM/DM, where RM and DM are the rotation and dispersion measure of the pulsar. However, this assumes that the thermal electron density and magnetic field of the interstellar medium are uncorrelated. Using numerical
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Connection among environment, cloud-cloud collision speed, and star formation activity in the strongly barred galaxy NGC 1300 Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-16 Fumiya Maeda; Kouji Ohta; Yusuke Fujimoto; Asao Habe
Cloud-cloud collision (CCC) has been suggested as a mechanism to induce massive star formation. Recent simulations suggest that a CCC speed is different among galactic-scale environments, which is responsible for observed differences in star formation activity. In particular, a high-speed CCC is proposed as a cause of star formation suppression in the bar regions in barred spiral galaxies. Focusing
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Two years of pulsar observations with the Ultra-Wideband Receiver on the Parkes radio telescope Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-16 Simon Johnston; C Sobey; S Dai; M Keith; M Kerr; R N Manchester; L S Oswald; A Parthasarathy; R M Shannon; P Weltevrede
The major programme for observing young, non-recycled pulsars with the Parkes telescope has transitioned from a narrow-band system to an ultra-wideband system capable of observing between 704 and 4032 MHz. We report here on the initial two years of observations with this receiver. Results include dispersion measure (DM) and Faraday rotation measure (RM) variability with time, determined with higher
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A faster Fourier transform? Computing small-scale power spectra and bispectra for cosmological simulations in 𝒪(N2) time Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-18 Oliver H E Philcox
We present |$\mathcal {O}(N^2)$| estimators for the small-scale power spectrum and bispectrum in cosmological simulations. In combination with traditional methods, these allow spectra to be efficiently computed across a vast range of scales, requiring orders of magnitude less computation time than Fast Fourier Transform based approaches alone. These methods are applicable to any tracer; simulation
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Shock-powered radio precursors of neutron star mergers from accelerating relativistic binary winds Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-14 Sridhar N, Zrake J, Metzger B, et al.
ABSTRACTDuring the final stages of a compact object merger, if at least one of the binary components is a magnetized neutron star (NS), then its orbital motion substantially expands the NS’s open magnetic flux – and hence increases its wind luminosity – relative to that of an isolated pulsar. As the binary orbit shrinks due to gravitational radiation, the power and speed of this binary-induced inspiral
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Measuring stellar atmosphere parameters using follow-up polarimetric microlensing observations Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-14 Khalouei E, Sajadian S, Rahvar S.
ABSTRACTWe present an analysis of potential follow-up polarimetric microlensing observations to study the stellar atmospheres of distant stars. First, we produce synthetic microlensing events using the Galactic model, stellar population and interstellar dust toward the Galactic bulge. We simulate the polarization microlensing light curves and pass them through the instrument specifications of the FOcal
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The physical properties and evolution of the interacting system AM 1204−292 Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-13 Rosa D, Rodrigues I, Krabbe A, et al.
ABSTRACTWe investigate interaction effects in the stellar and gas kinematics, stellar population, and ionized gas properties of the interacting galaxy pair AM 1204−292,composed of NGC 4105 and NGC 4106. The data consist of long-slit spectra in the range 3000–7050 Å. The massive E3 galaxy NGC 4105 presents a flat stellar velocity profile, while the ionized gas is in strong rotation, suggesting an external
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Properties of polarized synchrotron emission from fluctuation-dynamo action – I. Application to galaxy clusters Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-12 Sur S, Basu A, Subramanian K.
ABSTRACTUsing magnetohydrodynamic simulations of fluctuation dynamos, we perform broad-bandwidth synthetic observations to investigate the properties of polarized synchrotron emission and the role that Faraday rotation plays in inferring the polarized structures in the intracluster medium (ICM) of galaxy clusters. In the saturated state of the dynamo, we find a Faraday depth (FD) dispersion σFD ≈ 100
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Erratum: The tale of the tail – disentangling the high transverse velocity stars in Gaia DR2 Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2021-01-12 Amarante J, Smith M, Boeche C.
errata, addendaGalaxy: discGalaxy: haloGalaxy: kinematics and dynamics
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Evolution of gas disc–embedded intermediate mass ratio inspirals in the LISA band Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-29 Derdzinski A, D’Orazio D, Duffell P, et al.
ABSTRACTAmong the potential milliHz gravitational wave (GW) sources for the upcoming space-based interferometer LISA are extreme- or intermediate-mass ratio inspirals (EMRI/IMRIs). These events involve the coalescence of supermassive black holes in the mass range 105M⊙ ≲ M ≲ 107M⊙ with companion BHs of much lower masses. A subset of E/IMRIs are expected to occur in the accretion discs of active galactic
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Baryonic effects on the detectability of annihilation radiation from dark matter subhaloes around the Milky Way Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-26 Grand R, White S.
ABSTRACTWe use six, high-resolution Λ-cold dark matter (ΛCDM) simulations of galaxy formation to study how emission from dark matter annihilation is affected by baryonic processes. These simulations produce isolated, disc-dominated galaxies with structure, stellar populations, and stellar and halo masses comparable to those of the Milky Way. They resolve dark matter structures with mass above ∼106
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Using optical spectroscopy to map the geometry and structure of the irradiated accretion discs in low-mass X-ray binaries: the pilot study of MAXI J0637–430 Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-24 Tetarenko B, Shaw A, Manrow E, et al.
ABSTRACTThe recurring transient outbursts in low-mass X-ray binaries (LMXBs) provide us with strong test-beds for constraining the poorly understood accretion process. While impossible to image directly, phase-resolved spectroscopy can provide a powerful diagnostic to study their highly complex, time-dependent accretion discs. We present an 8-month long multiwavelength (UV, optical, X-ray) monitoring
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Joint inference on the redshift distribution of fast radio burst and on the intergalactic baryon content Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-24 Hackstein S, Brüggen M, Vazza F.
ABSTRACTFast radio bursts are transient radio pulses of extragalactic origin. Their dispersion measure is indicative of the baryon content in the ionized intergalactic medium between the source and the observer. However, inference using unlocalized fast radio bursts is degenerate to the distribution of redshifts of host galaxies. We perform a joint inference of the intergalactic baryon content and
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Circularization of tidal debris around white dwarfs: implications for gas production and dust variability Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-23 Malamud U, Grishin E, Brouwers M.
ABSTRACTWhite dwarf (WD) pollution is thought to arise from the tidal disruption of planetary bodies. The initial fragment stream is extremely eccentric, while observational evidence suggest that discs are circular or nearly so. Here, we propose a novel mechanism to bridge this gap and show that the fragments can rapidly circularize through dust or gas drag when they interact with a pre-existing compact
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Determining star formation rates in active galactic nuclei hosts via stellar population synthesis Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-21 Riffel R, Mallmann N, Ilha G, et al.
ABSTRACTThe effect of active galactic nuclei (AGNs) feedback on the host galaxy, and its role in quenching or enhancing star formation, is still uncertain due to the fact that usual star formation rate (SFR) indicators – emission-line luminosities based on the assumption of photoionization by young stars – cannot be used for active galaxies as the ionizing source is the AGN. We thus investigate the
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Simulating the inflation of bubbles by late jets in core collapse supernova ejecta Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-21 Akashi M, Soker N.
ABSTRACTWe conducted 3D hydrodynamical simulations to study the interaction of two late opposite jets with the ejecta of a core collapse supernova (CCSN), and study the bipolar structure that results from this interaction as the jets inflate hot-low-density bubbles. The newly born central object, a neutron star (NS; or a black hole), launches these jets at about 50 to 100 d after explosion. The bubbles
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Simulation-based inference of dynamical galaxy cluster masses with 3D convolutional neural networks Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-21 Kodi Ramanah D, Wojtak R, Arendse N.
ABSTRACTWe present a simulation-based inference framework using a convolutional neural network to infer dynamical masses of galaxy clusters from their observed 3D projected phase-space distribution, which consists of the projected galaxy positions in the sky and their line-of-sight velocities. By formulating the mass estimation problem within this simulation-based inference framework, we are able to
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DO-CRIME: dynamic on-sky covariance random interaction matrix evaluation, a novel method for calibrating adaptive optics systems Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-21 Lai O, Chun M, Dungee R, et al.
ABSTRACTAdaptive optics (AO) systems require a calibration procedure to operate, whether in closed loop or even more importantly in forward control. This calibration usually takes the form of an interaction matrix and is a measure of the response on the wavefront sensor (WFS) to wavefront corrector stimulus. If this matrix is sufficiently well conditioned, it can be inverted to produce a control matrix
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Thick disc molecular gas fraction in NGC 6946 Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-21 Patra N.
ABSTRACTSeveral recent studies reinforce the existence of a thick molecular disc in galaxies along with the dynamically cold thin disc. Assuming a two-component molecular disc, we model the disc of NGC 6946 as a four-component system consisting of stars, H i, thin disc molecular gas, and thick disc molecular gas in vertical hydrostatic equilibrium. Following, we set up the joint Poisson–Boltzmann equation
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Accretion and outflow activity in proto-brown dwarfs Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-21 Riaz B, Bally J.
ABSTRACTWe present a near-infrared study of accretion and outflow activity in six Class 0/I proto-brown dwarfs (proto-BDs) using VLT/SINFONI spectroscopy and spectroimaging observations. The spectra show emission in several [Fe ii] and H2 lines associated with jet/outflow activity, and in the accretion diagnostics of Pa β and Br γ lines. The peak velocities of the [Fe ii] lines (>100 km s−1) are higher
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Gibbs point process model for young star clusters in M33 Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-21 Li D, Barmby P.
ABSTRACTWe demonstrate the power of Gibbs point process models from the spatial statistics literature when applied to studies of resolved galaxies. We conduct a rigorous analysis of the spatial distributions of objects in the star formation complexes of M33, including giant molecular clouds (GMCs) and young stellar cluster candidates (YSCCs). We choose a hierarchical model structure from GMCs to YSCCs
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Improving sampling and calibration of gamma-ray bursts as distance indicators Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-21 Montiel A, Cabrera J, Hidalgo J.
ABSTRACTWe present a sample of 74 gamma-ray bursts (GRBs) from the Fermi-GBM catalogue for which we compute the distance moduli and use them to constrain effective dark energy models. To overcome the circularity problem affecting GRBs as distance indicators, we calibrate the Amati relation of our sample with a cosmology-independent technique. Specifically, we use the latest observational Hubble parameter
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Clustering in the simulated H α galaxy redshift survey from Nancy Grace Roman Space Telescope Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-21 Zhai Z, Chuang C, Wang Y, et al.
ABSTRACTWe present a realistic 2000 deg2 H α galaxy mock catalogue with 1 < z < 2 for the Nancy Grace Roman Space Telescope (Roman) galaxy redshift survey, the High Latitude Spectroscopic Survey (HLSS), created using Galacticus, a semi-analytical galaxy formation model, and high-resolution cosmological N-body simulations. Galaxy clustering can probe dark energy and test gravity via baryon acoustic
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A machine-learning approach for classifying low-mass X-ray binaries based on their compact object nature Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-21 Pattnaik R, Sharma K, Alabarta K, et al.
ABSTRACTLow-mass X-ray binaries (LMXBs) are binary systems where one of the components is either a black hole or a neutron star and the other is a less massive star. It is challenging to unambiguously determine whether an LMXB hosts a black hole or a neutron star. In the last few decades, multiple observational works have tried, with different levels of success, to address this problem. In this paper
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Proplyds in the flame nebula NGC 2024 Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-21 Haworth T, Kim J, Winter A, et al.
ABSTRACTA recent survey of the inner 0.35 × 0.35 pc of the NGC 2024 star-forming region revealed two distinct millimetre continuum disc populations that appear to be spatially segregated by the boundary of a dense cloud. The eastern (and more embedded) population is ∼0.2–0.5 Myr old, with an ALMA mm continuum disc detection rate of about $45\,$ per cent. However, this drops to only $\sim 15\,$ per cent
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Magnetic field and chromospheric activity evolution of HD 75332: a rapid magnetic cycle in an F star without a hot Jupiter Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-18 Brown E, Marsden S, Mengel M, et al.
ABSTRACTStudying cool star magnetic activity gives an important insight into the stellar dynamo and its relationship with stellar properties, as well as allowing us to place the Sun’s magnetism in the context of other stars. Only 61 Cyg A (K5V) and τ Boo (F8V) are currently known to have magnetic cycles like the Sun’s, where the large-scale magnetic field polarity reverses in phase with the star’s
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A physico-chemical model to study the ion density distribution in the inner coma of comet C/2016 R2 (Pan-STARRS) Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-18 Raghuram S, Bhardwaj A, Hutsemékers D, et al.
ABSTRACTThe recent observations show that comet C/2016 R2 (Pan-Starrs) has a unique and peculiar composition when compared with several other comets observed at 2.8 au heliocentric distance. Assuming solar resonance fluorescence is the only excitation source, the observed ionic emission intensity ratios are used to constrain the corresponding neutral abundances in this comet. We developed a physico-chemical
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The correlation between impact crater ages and chronostratigraphic boundary dates Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-18 Firestone R.
ABSTRACTThe accurately measured ages of 89 large impact craters and layers were compared with the boundary dates for periods, epochs, and ages of the geological time-scale by a weighted least-squares fit. They are highly correlated with a χ2/f = 0.63. A Monte Carlo simulation of randomly chosen crater ages gives a >99.8 per cent probability that this result is not random. No craters are found in the
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Dissecting the stellar content of Leo I: a dwarf irregular caught in transition Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-17 Ruiz-Lara T, Gallart C, Monelli M, et al.
ABSTRACTLeo I is considered one of the youngest dwarf spheroidals (dSph) in the Local Group. Its isolation, extended star formation history (SFH), and recent perigalacticon passage (∼1 Gyr ago) make Leo I one of the most interesting nearby stellar systems. Here, we analyse deep photometric Hubble Space Telescope data via colour–magnitude diagram fitting techniques to study its global and radially resolved
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An ALMA/NOEMA survey of the molecular gas properties of high-redshift star-forming galaxies Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-17 Birkin J, Weiss A, Wardlow J, et al.
ABSTRACTWe have used ALMA and NOEMA to study the molecular gas reservoirs in 61 ALMA-identified submillimetre galaxies (SMGs) in the COSMOS, UDS, and ECDFS fields. We detect 12CO ($J_{\rm up} =$ 2–5) emission lines in 50 sources, and [C i](3P1 − 3P0) emission in eight, at $z =$ 1.2–4.8 and with a median redshift of 2.9 ± 0.2. By supplementing our data with literature sources, we construct a statistical
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High-resolution observations of molecular emission lines toward the CI Tau proto-planetary disc: planet-carved gaps or shadowing? Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-17 Rosotti G, Ilee J, Facchini S, et al.
ABSTRACTRecent observations have revealed that most proto-planetary discs show a pattern of bright rings and dark gaps. However, most of the high-resolution observations have focused only on the continuum emission. In this paper, we present high-resolution ALMA band 7 (0.89 mm) observations of the disc around the star CI Tau in the 12CO & 13CO J = 3–2 and CS J = 7–6 emission lines. Our recent work
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emerge: empirical predictions of galaxy merger rates since z ∼ 6 Mon. Not. R. Astron. Soc. (IF 5.356) Pub Date : 2020-12-17 O’Leary J, Moster B, Naab T, et al.
ABSTRACTWe explore the galaxy–galaxy merger rate with the empirical model for galaxy formation, emerge. On average, we find that between 2 per cent and 20 per cent of massive galaxies (log10(m*/M⊙) ≥ 10.3) will experience a major merger per Gyr. Our model predicts galaxy merger rates that do not scale as a power law with redshift when selected by descendant stellar mass, and exhibit a clear stellar