August 2021 (Page 61)

Binary evolution pathways of Blue Large-Amplitude Pulsators. (arXiv:2107.14628v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Byrne_C/0/1/0/all/0/1">C. M. Byrne</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stanway_E/0/1/0/all/0/1">E. R. Stanway</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Eldridge_J/0/1/0/all/0/1">J. J. Eldridge</a> Blue Large-Amplitude Pulsators (BLAPs) are a recently discovered class of pulsating star, believed to be proto-white dwarfs, produced by mass stripping of a red giant when it has a small helium core. An outstanding question is why the stars in this class of pulsator seem to form two distinct groups by surface gravity, despite predictions that stars in the gap between them should also pulsate. We use a binary population synthesis model to identify potential evolutionary pathways that a star can take to becomeRead More →

Coupling and recoupling of binaries in chaotic three body systems. (arXiv:2107.14627v1 [nlin.CD]) <a href="http://arxiv.org/find/nlin/1/au:+Venkatesh_T/0/1/0/all/0/1">T.S.Sachin Venkatesh</a> Three body systems where one of the bodies is ejected without escaping the binary system have previously been studied in various restricted forms. However, none of these studies dwells on the problem in a general setting. Thus, to study this phenomenon qualitatively, we try to expand this problem’s scope to unequal mass systems and generalize them by considering various configurations of fixed initial points with precisely calculated initial velocities, some zero velocity models, and some optimized models. We will see the use of terminology similar to the previous studies doneRead More →

The Origin of Rest-mass Energy. (arXiv:2107.14626v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Melia_F/0/1/0/all/0/1">Fulvio Melia</a> Today we have a solid, if incomplete, physical picture of how inertia is created in the standard model. We know that most of the visible baryonic `mass’ in the Universe is due to gluonic back-reaction on accelerated quarks, the latter of which attribute their own inertia to a coupling with the Higgs field — a process that elegantly and self-consistently also assigns inertia to several other particles. But we have never had a physically viable explanation for the origin of rest-mass energy, in spite of many attempts at understanding it towards the end of theRead More →

Follow-up of non-transiting planets detected by Kepler. Confirmation of three hot-Jupiters and validation of three other planets. (arXiv:2107.14621v1 [astro-ph.EP]) <a href="http://arxiv.org/find/astro-ph/1/au:+Lillo_Box_J/0/1/0/all/0/1">J. Lillo-Box</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Millholland_S/0/1/0/all/0/1">S. Millholland</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Laughlin_G/0/1/0/all/0/1">G. Laughlin</a> The direct detection of new extrasolar planets from high-precision photometry data is commonly based on the observation of the transit signal of the planet as it passes in front of its star. Close-in planets, however, leave additional imprints in the light curve even if they do not transit. These are the so-called phase curve variations that include ellipsoidal, reflection and beaming effects. In Millholland & Laughlin (2017), the authors scrutinized the Kepler database looking for these phaseRead More →

Stability Analysis of Relativistic Polytropes. (arXiv:2107.14618v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Saad_A/0/1/0/all/0/1">A. S. Saad</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Nouh_M/0/1/0/all/0/1">M. I. Nouh</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Shaker_A/0/1/0/all/0/1">A. A. Shaker</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Kamel_T/0/1/0/all/0/1">T. M. Kamel</a> A main question in astrophysics and cosmology has been the severe stability of the astrophysical objects, whether a particular equilibrium configuration is stable. In this article, we study the relativistic self-gravitating, hydrostatic spheres with a polytropic equation of state , considering structures with the polytropic indices and illustrates the results for the relativistic parameters . We determined the critical relativistic parameter at which the mass of the polytrope has a maximum value and represents the first mode of radial instability. For n=1Read More →

From NANOGrav to LIGO with metastable cosmic strings. (arXiv:2009.10649v3 [astro-ph.CO] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Buchmuller_W/0/1/0/all/0/1">Wilfried Buchmuller</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Domcke_V/0/1/0/all/0/1">Valerie Domcke</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Schmitz_K/0/1/0/all/0/1">Kai Schmitz</a> We interpret the recent NANOGrav results in terms of a stochastic gravitational wave background from metastable cosmic strings. The observed amplitude of a stochastic signal can be translated into a range for the cosmic string tension and the mass of magnetic monopoles arising in theories of grand unification. In a sizable part of the parameter space, this interpretation predicts a large stochastic gravitational wave signal in the frequency band of ground-based interferometers, which can be probed in the very near future. We confront these resultsRead More →

Dark Energy Survey Year 3 Results: Covariance Modelling and its Impact on Parameter Estimation and Quality of Fit. (arXiv:2012.08568v3 [astro-ph.CO] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Friedrich_O/0/1/0/all/0/1">O. Friedrich</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Andrade_Oliveira_F/0/1/0/all/0/1">F. Andrade-Oliveira</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Camacho_H/0/1/0/all/0/1">H. Camacho</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Alves_O/0/1/0/all/0/1">O. Alves</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rosenfeld_R/0/1/0/all/0/1">R. Rosenfeld</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sanchez_J/0/1/0/all/0/1">J. Sanchez</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fang_X/0/1/0/all/0/1">X. Fang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Eifler_T/0/1/0/all/0/1">T. F. Eifler</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Krause_E/0/1/0/all/0/1">E. Krause</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chang_C/0/1/0/all/0/1">C. Chang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Omori_Y/0/1/0/all/0/1">Y. Omori</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Amon_A/0/1/0/all/0/1">A. Amon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Baxter_E/0/1/0/all/0/1">E. Baxter</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Elvin_Poole_J/0/1/0/all/0/1">J. Elvin-Poole</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Huterer_D/0/1/0/all/0/1">D. Huterer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Porredon_A/0/1/0/all/0/1">A. Porredon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Prat_J/0/1/0/all/0/1">J. Prat</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Terra_V/0/1/0/all/0/1">V. Terra</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Troja_A/0/1/0/all/0/1">A. Troja</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Alarcon_A/0/1/0/all/0/1">A. Alarcon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bechtol_K/0/1/0/all/0/1">K. Bechtol</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bernstein_G/0/1/0/all/0/1">G. M. Bernstein</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Buchs_R/0/1/0/all/0/1">R. Buchs</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Campos_A/0/1/0/all/0/1">A. Campos</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rosell_A/0/1/0/all/0/1">A. Carnero Rosell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kind_M/0/1/0/all/0/1">M. Carrasco Kind</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cawthon_R/0/1/0/all/0/1">R.Read More →

Revisiting the AMS-02 antiproton excess: The role of correlated errors. (arXiv:2107.14606v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Heisig_J/0/1/0/all/0/1">Jan Heisig</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Korsmeier_M/0/1/0/all/0/1">Michael Korsmeier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Winkler_M/0/1/0/all/0/1">Martin Wolfgang Winkler</a> Cosmic-ray antiprotons are a remarkable diagnostic tool for the study of astroparticle physics’ processes in our Galaxy. While the bulk of measured antiprotons is consistent with a secondary origin, several studies have found evidence for a subdominant primary component in the AMS-02 data. In this proceedings article, we revisit the excess considering systematic errors that could affect the signal. Of particular importance are unknown correlations in the AMS-02 systematic errors, the dominant of which are associated with the cross sections for cosmic-ray absorptionRead More →

Neutrinos from charm: forward production at the LHC and in the atmosphere. (arXiv:2107.01178v2 [hep-ph] UPDATED) <a href="http://arxiv.org/find/hep-ph/1/au:+Jeong_Y/0/1/0/all/0/1">Yu Seon Jeong</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Bai_W/0/1/0/all/0/1">Weidong Bai</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Diwan_M/0/1/0/all/0/1">Milind Diwan</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Garzelli_M/0/1/0/all/0/1">Maria Vittoria Garzelli</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Kumar_F/0/1/0/all/0/1">Fnu Karan Kumar</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Reno_M/0/1/0/all/0/1">Mary Hall Reno</a> Theoretical predictions of the prompt atmospheric neutrino flux have large uncertainties associated with charm hadron production, by far the dominant source of prompt neutrinos in the atmosphere. The flux of cosmic rays, with its steeply falling energy spectrum, weights the forward production of charm in the evaluation of the atmospheric neutrino flux at high energies. The current LHCb experiment at CERN constrains charm production in kinematic regions relevantRead More →

Detecting shock waves in non-fundamental mode RR Lyrae using large sample of spectra in SDSS and LAMOST. (arXiv:2012.14444v1 [astro-ph.SR] CROSS LISTED) <a href="http://arxiv.org/find/astro-ph/1/au:+Duan_X/0/1/0/all/0/1">Xiao-Wei Duan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_X/0/1/0/all/0/1">Xiao-Dian Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Deng_L/0/1/0/all/0/1">Li-Cai Deng</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yang_F/0/1/0/all/0/1">Fan Yang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_C/0/1/0/all/0/1">Chao Liu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bhardwaj_A/0/1/0/all/0/1">Anupam Bhardwaj</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_H/0/1/0/all/0/1">Hua-Wei Zhang</a> Steps toward the nature inside RR Lyrae variables can not only improve our understanding of variable stars but also innovate the precision when we use them as tracers to map the structure of the universe. In this work, we develop a hand-crafted one-dimensional pattern recognition pipeline to fetch out the “first apparitions”, the most prominent observational characteristic of shock. We report the firstRead More →

A HARPS-N mass for the elusive Kepler-37d: a case study in disentangling stellar activity and planetary signals. (arXiv:2107.13900v2 [astro-ph.EP] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Rajpaul_V/0/1/0/all/0/1">V. M. Rajpaul</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Buchhave_L/0/1/0/all/0/1">L. A. Buchhave</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lacedelli_G/0/1/0/all/0/1">G. Lacedelli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rice_K/0/1/0/all/0/1">K. Rice</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mortier_A/0/1/0/all/0/1">A. Mortier</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Malavolta_L/0/1/0/all/0/1">L. Malavolta</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aigrain_S/0/1/0/all/0/1">S. Aigrain</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Borsato_L/0/1/0/all/0/1">L. Borsato</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mayo_A/0/1/0/all/0/1">A. W. Mayo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Charbonneau_D/0/1/0/all/0/1">D. Charbonneau</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Damasso_M/0/1/0/all/0/1">M. Damasso</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dumusque_X/0/1/0/all/0/1">X. Dumusque</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ghedina_A/0/1/0/all/0/1">A. Ghedina</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Latham_D/0/1/0/all/0/1">D. W. Latham</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lopez_Morales_M/0/1/0/all/0/1">M. L&#xf3;pez-Morales</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Magazzu_A/0/1/0/all/0/1">A. Magazz&#xf9;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Micela_G/0/1/0/all/0/1">G. Micela</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Molinari_E/0/1/0/all/0/1">E. Molinari</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pepe_F/0/1/0/all/0/1">F. Pepe</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Piotto_G/0/1/0/all/0/1">G. Piotto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Poretti_E/0/1/0/all/0/1">E. Poretti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Rowther_S/0/1/0/all/0/1">S. Rowther</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sozzetti_A/0/1/0/all/0/1">A. Sozzetti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Udry_S/0/1/0/all/0/1">S. Udry</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Watson_C/0/1/0/all/0/1">C. A. Watson</a> To date, only 18 exoplanetsRead More →

Spectral signature of mass outflow in Two Component Advective Flow Paradigm. (arXiv:2107.13808v2 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Mondal_S/0/1/0/all/0/1">Santanu Mondal</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chakrabarti_S/0/1/0/all/0/1">Sandip K. Chakrabarti</a> Outflows are common in many astrophysical systems. In the Two Component Advective Flow ({fontfamily{qcr}selectfont TCAF}) paradigm which is essentially a generalized Bondi flow including rotation, viscosity and cooling effects, the outflow is originated from the hot, puffed up, post-shock region at the inner edge of the accretion disk. We consider this region to be the base of the jet carrying away matter with high velocity. In this paper, we study the spectral properties of black holes using {fontfamily{qcr}selectfont TCAF} which includes also a jetRead More →

A detection of circumgalactic gas with fast radio bursts. (arXiv:2107.13692v2 [astro-ph.GA] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Connor_L/0/1/0/all/0/1">Liam Connor</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ravi_V/0/1/0/all/0/1">Vikram Ravi</a> Galaxies and groups of galaxies exist in dark-matter halos filled with diffuse gas. The diffuse gas represents up to 80% of the mass in luminous matter within the halos (1,2), and is difficult to detect because of its low density (particle number densities of $lesssim10^{-4}$,cm$^{-3}$) and high temperature (mostly greater than $10^{6}$,K). The spatial distribution and total mass of this material determines, and is influenced by, the evolution of galaxies and galaxy groups (3-5). Existing observational constraints on these quantities are limited by sensitivity, and the necessityRead More →

The Global Meteor Network — Methodology and First Results. (arXiv:2107.12335v3 [astro-ph.EP] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Vida_D/0/1/0/all/0/1">Denis Vida</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Segon_D/0/1/0/all/0/1">Damir &#x160;egon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gural_P/0/1/0/all/0/1">Peter S. Gural</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Brown_P/0/1/0/all/0/1">Peter G. Brown</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+McIntyre_M/0/1/0/all/0/1">Mark J.M. McIntyre</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dijkema_T/0/1/0/all/0/1">Tammo Jan Dijkema</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pavletic_L/0/1/0/all/0/1">Lovro Pavleti&#x107;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kukic_P/0/1/0/all/0/1">Patrik Kuki&#x107;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mazur_M/0/1/0/all/0/1">Michael J. Mazur</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Eschman_P/0/1/0/all/0/1">Peter Eschman</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Roggemans_P/0/1/0/all/0/1">Paul Roggemans</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Merlak_A/0/1/0/all/0/1">Aleksandar Merlak</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zubovic_D/0/1/0/all/0/1">Dario Zubovi&#x107;</a> The Global Meteor Network (GMN) utilizes highly sensitive low-cost CMOS video cameras which run open-source meteor detection software on Raspberry Pi computers. Currently, over 450 GMN cameras in 30 countries are deployed. The main goal of the network is to provide long-term characterization of the radiants, flux, and sizeRead More →

Precision cosmology and the stiff-amplified gravitational-wave background from inflation: NANOGrav, Advanced LIGO-Virgo and the Hubble tension. (arXiv:2107.12229v2 [astro-ph.CO] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Li_B/0/1/0/all/0/1">Bohua Li</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shapiro_P/0/1/0/all/0/1">Paul R. Shapiro</a> The recent NANOGrav finding of a common-spectrum process has invited interpretations as possible evidence of a primordial stochastic gravitational-wave background (SGWB) stronger than predicted by standard inflation+LCDM. Such an SGWB would contribute an extra radiation component to the background Universe which may affect its expansion history. As such, it may help alleviate the current Hubble tension, a novel connection between gravitational waves and cosmology. We demonstrate this by considering a cosmological model, the “standard inflation + stiff amplification” scenario,Read More →