August 2021 (Page 62)

Non-locality of the Turbulent Electromotive Force. (arXiv:2107.10625v2 [astro-ph.GA] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Bendre_A/0/1/0/all/0/1">Abhijit B. Bendre</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Subramanian_K/0/1/0/all/0/1">Kandaswamy Subramanian</a> The generation of large-scale magnetic fields ($overline{mathbf{B}}$) in astrophysical systems is driven by the mean turbulent electromotive force ($overline{{cal E}}$), the cross correlation between local fluctuations of velocity and magnetic fields. This can depend non-locally on $overline{mathbf{B}}$ through a convolution kernel $K_{ij}$. In a new approach to find $K_{ij}$, we directly fit the time series data of $overline{{cal E}}$ versus $overline{mathbf{B}}$ from a galactic dynamo simulation using singular value decomposition. We calculate the usual turbulent transport coefficients as moments of $K_{ij}$, show the importance of including non-locality over eddyRead More →

Generalized Redundant Calibration of Radio Inteferferometers. (arXiv:2107.10186v2 [astro-ph.IM] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Adari_P/0/1/0/all/0/1">Prakruth Adari</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Slosar_A/0/1/0/all/0/1">An&#x17e;e Slosar</a> Redundant calibration is a technique in radio astronomy that allows calibration of radio arrays, whose antennas lie on a lattice by exploiting the fact that redundant baselines should see the same sky signal. Because the number of measured visibilities scales quadratically with the number of antennas, but the number of unknowns describing the individual antenna responses and the available information about the sky scale only linearly with the array size, the problem is always over-constrained as long as the array is big and dense enough. This is true even forRead More →

EC 22536-5304: a lead-rich and metal-poor long-period binary. (arXiv:2107.06340v2 [astro-ph.SR] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Dorsch_M/0/1/0/all/0/1">M. Dorsch</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jeffery_C/0/1/0/all/0/1">C. S. Jeffery</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Irrgang_A/0/1/0/all/0/1">A. Irrgang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Woolf_V/0/1/0/all/0/1">V. Woolf</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Heber_U/0/1/0/all/0/1">U. Heber</a> Helium-burning hot subdwarf stars of spectral types O and B (sdO/B) are thought to be produced through various types of binary interaction. The helium-rich hot subdwarf star EC22536-5304 was recently found to be extremely enriched in lead. Here, we show that EC22536-5304 is a binary star with a metal-poor subdwarf F-type (sdF) companion. We have performed a detailed analysis of high-resolution SALT/HRS and VLT/UVES spectra, deriving metal abundances for the hot subdwarf, as well as atmospheric parameters forRead More →

Implications of a rapidly varying FRB in a globular cluster of M81. (arXiv:2107.04059v2 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Lu_W/0/1/0/all/0/1">Wenbin Lu</a> (Princeton), <a href="http://arxiv.org/find/astro-ph/1/au:+Beniamini_P/0/1/0/all/0/1">Paz Beniamini</a> (Caltech), <a href="http://arxiv.org/find/astro-ph/1/au:+Kumar_P/0/1/0/all/0/1">Pawan Kumar</a> (UT Austin) The recent discovery of a fast radio burst (FRB) in a globular cluster of M81 points to more than one channels for the formation of objects that produce these powerful radio pulses. Association of an FRB to a globular cluster (or other old stellar systems) suggests that strongly magnetized neutron stars, which are the most likely objects responsible for these bursts, are born not only when young massive stars undergo core-collapse, but also by mergers of oldRead More →

The PDF perspective on the tracer-matter connection: Lagrangian bias and non-Poissonian shot noise. (arXiv:2107.02300v2 [astro-ph.CO] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Friedrich_O/0/1/0/all/0/1">Oliver Friedrich</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Halder_A/0/1/0/all/0/1">Anik Halder</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Boyle_A/0/1/0/all/0/1">Aoife Boyle</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Uhlemann_C/0/1/0/all/0/1">Cora Uhlemann</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Britt_D/0/1/0/all/0/1">Dylan Britt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Codis_S/0/1/0/all/0/1">Sandrine Codis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gruen_D/0/1/0/all/0/1">Daniel Gruen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hahn_C/0/1/0/all/0/1">ChangHoon Hahn</a> We study the connection of matter density and its tracers from the PDF perspective. One aspect of this connection is the conditional expectation value $langle delta_{mathrm{tracer}}|delta_mrangle$ when averaging both tracer and matter density over some scale. We present a new way to incorporate a Lagrangian bias expansion of this expectation value into standard frameworks for modelling the PDF of density fluctuations and counts-in-cells statistics. UsingRead More →

No Detectable Kilonova Counterpart is Expected for O3 Neutron Star-Black Hole Candidates. (arXiv:2106.15781v2 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Zhu_J/0/1/0/all/0/1">Jin-Ping Zhu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wu_S/0/1/0/all/0/1">Shichao Wu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yang_Y/0/1/0/all/0/1">Yuan-Pei Yang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_B/0/1/0/all/0/1">Bing Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yu_Y/0/1/0/all/0/1">Yun-Wei Yu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gao_H/0/1/0/all/0/1">He Gao</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cao_Z/0/1/0/all/0/1">Zhoujian Cao</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_L/0/1/0/all/0/1">Liang-Duan Liu</a> We analyse the tidal disruption probability of potential neutron star–black hole (NSBH) merger gravitational wave (GW) events, including GW190426_152155, GW190814, GW200105_162426 and GW200115_042309, detected during the third observing run of the LIGO/Virgo Collaboration, and the detectability of kilonova emission in connection with these events. The posterior distributions of GW190814 and GW200105_162426 show that they must be plunging events and hence no kilonova signal is expected fromRead More →

Common envelope jets supernovae with a black hole companion as possible high energy neutrino sources. (arXiv:2101.05118v2 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Grichener_A/0/1/0/all/0/1">Aldana Grichener</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Soker_N/0/1/0/all/0/1">Noam Soker</a> (Technion, Israel) We study high energy neutrino emission from relativistic jets launched by a black hole (BH) spiraling-in inside the envelope of a red supergiant (RSG), and find that such common envelope jets supernovae (CEJSNe) are a potential source for the ~10^15 eV neutrinos detected by IceCube. We first use the stellar evolution code MESA to mimic the effect of the jets on the RSG envelope, and find that the jets substantially inflate the envelope. We then study the propagation ofRead More →

Hunting for the nature of the enigmatic narrow-line Seyfert 1 galaxy PKS 2004-447. (arXiv:2106.12536v2 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Berton_M/0/1/0/all/0/1">M. Berton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Peluso_G/0/1/0/all/0/1">G. Peluso</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marziani_P/0/1/0/all/0/1">P. Marziani</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Komossa_S/0/1/0/all/0/1">S. Komossa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Foschini_L/0/1/0/all/0/1">L. Foschini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ciroi_S/0/1/0/all/0/1">S. Ciroi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_S/0/1/0/all/0/1">S. Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Congiu_E/0/1/0/all/0/1">E. Congiu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gallo_L/0/1/0/all/0/1">L.C. Gallo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bjorklund_I/0/1/0/all/0/1">I. Bj&#xf6;rklund</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Crepaldi_L/0/1/0/all/0/1">L. Crepaldi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mille_F/0/1/0/all/0/1">F. Di Mille</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jarvela_E/0/1/0/all/0/1">E. J&#xe4;rvel&#xe4;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kotilainen_J/0/1/0/all/0/1">J. Kotilainen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kreikenbohm_A/0/1/0/all/0/1">A. Kreikenbohm</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Morrell_N/0/1/0/all/0/1">N. Morrell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Romano_P/0/1/0/all/0/1">P. Romano</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sani_E/0/1/0/all/0/1">E. Sani</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Terreran_G/0/1/0/all/0/1">G. Terreran</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tornikoski_M/0/1/0/all/0/1">M. Tornikoski</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vercellone_S/0/1/0/all/0/1">S. Vercellone</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vietri_A/0/1/0/all/0/1">A. Vietri</a> Narrow-line Seyfert 1 (NLS1) galaxies are a class of active galactic nuclei (AGN) that, in some cases, can harbor powerful relativistic jets.Read More →

Bilby-MCMC: An MCMC sampler for gravitational-wave inference. (arXiv:2106.08730v2 [gr-qc] UPDATED) <a href="http://arxiv.org/find/gr-qc/1/au:+Ashton_G/0/1/0/all/0/1">Gregory Ashton</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Talbot_C/0/1/0/all/0/1">Colm Talbot</a> We introduce Bilby-MCMC, a Markov-Chain Monte-Carlo sampling algorithm tuned for the analysis of gravitational waves from merging compact objects. Bilby-MCMC provides a parallel-tempered ensemble Metropolis-Hastings sampler with access to a block-updating proposal library including problem-specific and machine learning proposals. We demonstrate that learning proposals can produce over a 10-fold improvement in efficiency by reducing the autocorrelation time. Using a variety of standard and problem-specific tests, we validate the ability of the Bilby-MCMC sampler to produce independent posterior samples and estimate the Bayesian evidence. Compared to the widely-used dynesty nestedRead More →

Please repeat: Strong lensing of gravitational waves as a probe of compact binary and galaxy populations. (arXiv:2105.14390v2 [astro-ph.CO] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Xu_F/0/1/0/all/0/1">Fei Xu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ezquiaga_J/0/1/0/all/0/1">Jose Maria Ezquiaga</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Holz_D/0/1/0/all/0/1">Daniel E. Holz</a> Strong gravitational lensing of gravitational wave sources offers a novel probe of both the lens galaxy and the binary source population. In particular, the strong lensing event rate and the time delay distribution of multiply-imaged gravitational-wave binary coalescence events can be used to constrain the mass distribution of the lenses as well as the intrinsic properties of the source population. We calculate the strong lensing event rate for a range of second (2G) and thirdRead More →

Neutral CGM as damped Ly{alpha} absorbers at high redshift. (arXiv:2105.06489v2 [astro-ph.GA] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Stern_J/0/1/0/all/0/1">Jonathan Stern</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sternberg_A/0/1/0/all/0/1">Amiel Sternberg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Faucher_Giguere_C/0/1/0/all/0/1">Claude-Andr&#xe9; Faucher-Gigu&#xe8;re</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hafen_Z/0/1/0/all/0/1">Zachary Hafen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fielding_D/0/1/0/all/0/1">Drummond Fielding</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Quataert_E/0/1/0/all/0/1">Eliot Quataert</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wetzel_A/0/1/0/all/0/1">Andrew Wetzel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Angles_Alcazar_D/0/1/0/all/0/1">Daniel Angl&#xe9;s-Alc&#xe1;zar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+El_Badry_K/0/1/0/all/0/1">Kareem El-Badry</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Keres_D/0/1/0/all/0/1">Du&#x161;an Kere&#x161;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hopkins_P/0/1/0/all/0/1">Philip F. Hopkins</a> Recent searches for the hosts of high-redshift ($z sim 4$) damped Ly$alpha$ absorbers (DLAs) have detected bright galaxies at distances of tens of kpc from the DLA. Using the FIRE-2 cosmological zoom simulations, we argue that these relatively large distances are due to a predominantly cool and neutral inner circumgalactic medium (CGM) surrounding high-redshift galaxies. The inner CGM isRead More →

Ultra-Heavy Dark Matter Search with Electron Microscopy of Geological Quartz. (arXiv:2105.03998v2 [hep-ph] UPDATED) <a href="http://arxiv.org/find/hep-ph/1/au:+Ebadi_R/0/1/0/all/0/1">Reza Ebadi</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Mathur_A/0/1/0/all/0/1">Anubhav Mathur</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Tanin_E/0/1/0/all/0/1">Erwin H. Tanin</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Tailby_N/0/1/0/all/0/1">Nicholas D. Tailby</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Marshall_M/0/1/0/all/0/1">Mason C. Marshall</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Ravi_A/0/1/0/all/0/1">Aakash Ravi</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Trubko_R/0/1/0/all/0/1">Raisa Trubko</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Fu_R/0/1/0/all/0/1">Roger R. Fu</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Phillips_D/0/1/0/all/0/1">David F. Phillips</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Rajendran_S/0/1/0/all/0/1">Surjeet Rajendran</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Walsworth_R/0/1/0/all/0/1">Ronald L. Walsworth</a> Self-interactions within the dark sector could clump dark matter into heavy composite states with low number density, leading to a highly suppressed event rate in existing direct detection experiments. However, the large interaction cross section between such ultra-heavy dark matter (UHDM) and standard model matter results in a distinctive and compelling signature: long,Read More →

On the origin of secondary bias: perspective from the correlation of halo properties with the linear density field. (arXiv:2104.10123v2 [astro-ph.CO] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_X/0/1/0/all/0/1">Xiaoyu Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_H/0/1/0/all/0/1">Huiyuan Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mo_H/0/1/0/all/0/1">H.J. Mo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shi_J/0/1/0/all/0/1">JingJing Shi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Jing_Y/0/1/0/all/0/1">Yipeng Jing</a> Using two sets of large $N$-body simulations, we study the origin of the correlations of halo assembly time ($z_{rm f}$), concentration ($v_{rm max}/v_{rm 200}$) and spin ($lambda$) with the large-scale evolved density field at given halo mass, i.e. the secondary bias. We find that the secondary bias is the secondary effect of the correlations of halo properties with the linear density estimated at the same comoving scale. Using theRead More →

ECLIPSE: a fast Quadratic Maximum Likelihood estimator for CMB intensity and polarization power spectra. (arXiv:2104.08528v2 [astro-ph.CO] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Bilbao_Ahedo_J/0/1/0/all/0/1">J. D. Bilbao-Ahedo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Barreiro_R/0/1/0/all/0/1">R. B. Barreiro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vielva_P/0/1/0/all/0/1">P. Vielva</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Martinez_Gonzalez_E/0/1/0/all/0/1">E. Mart&#xed;nez-Gonz&#xe1;lez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Herranz_D/0/1/0/all/0/1">D. Herranz</a> We present ECLIPSE (Efficient Cmb poLarization and Intensity Power Spectra Estimator), an optimized implementation of the Quadratic Maximum Likelihood (QML) method for the estimation of the power spectra of the Cosmic Microwave Background (CMB). This approach allows one to reduce significantly the computational costs associated to this technique, allowing to estimate the power spectra up to higher multipoles than previous implementations. In particular, for a resolution of $N_mathrm{side}=64$, $ell_{mathrm{max}}=192$ and aRead More →