August 2020

Astronomical Site Monitoring System at Lijiang Observatory. (arXiv:2004.12128v3 [astro-ph.IM] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Xin_Y/0/1/0/all/0/1">Yu-Xin Xin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bai_J/0/1/0/all/0/1">Jin-Ming Bai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lun_B/0/1/0/all/0/1">Bao-Li Lun</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fan_Y/0/1/0/all/0/1">Yu-Feng Fan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_C/0/1/0/all/0/1">Chuan-Jun Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_X/0/1/0/all/0/1">Xiao-Wei Liu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Yu_X/0/1/0/all/0/1">Xiao-Guang Yu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ye_K/0/1/0/all/0/1">Kai Ye</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Song_T/0/1/0/all/0/1">Teng-Fei Song</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chang_L/0/1/0/all/0/1">Liang Chang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+He_S/0/1/0/all/0/1">Shou-Sheng He</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mao_J/0/1/0/all/0/1">Ji-Rong Mao</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Xu_L/0/1/0/all/0/1">Liang Xu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Xiong_D/0/1/0/all/0/1">Ding-Rong Xiong</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_X/0/1/0/all/0/1">Xi-Liang Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_J/0/1/0/all/0/1">Jian-Guo Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ding_X/0/1/0/all/0/1">Xu Ding</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Feng_H/0/1/0/all/0/1">Hai-Cheng Feng</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Liu_X/0/1/0/all/0/1">Xiang-Kun Liu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Huang_Y/0/1/0/all/0/1">Yang Huang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_B/0/1/0/all/0/1">Bing-Qiu Chen</a> We installed two sets of Astronomical Site Monitoring System(ASMS) at Lijiang Observatory(GMG), for the running of the 2.4-meter Lijiang optical telescope(LJT) and the 1.6-meter Multi-channel Photometric Survey Telescope (Mephisto). The Mephistro isRead More →

GRB 200415A: magnetar giant flare or short gamma-ray burst?. (arXiv:2008.12752v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Minaev_P/0/1/0/all/0/1">Pavel Minaev</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pozanenko_A/0/1/0/all/0/1">Alexei Pozanenko</a> A detailed analysis of the GBM/Fermi experiment data is carried out to classify GRB 200415A. It is shown that, on the one hand, this event exhibits typical for type I (short) gamma-ray bursts (GRBs) properties, such as duration, variability, and the character of spectral evolution (lag). On the other hand, the localization of the event source on the celestial plane, obtained by the triangulation method (IPN), indicates the nearby ($ D_L $ = 3.5 Mpc) galaxy NGC 253 (Sculptor) as a possible host galaxy for this burst. ItRead More →

Center-to-Limb Variation of the Inverse Evershed Flow. (arXiv:2008.12748v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Beck_C/0/1/0/all/0/1">C. Beck</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Choudhary_D/0/1/0/all/0/1">D.P. Choudhary</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ranganathan_M/0/1/0/all/0/1">M. Ranganathan</a> We present the properties of the inverse Evershed flow (IEF) based on the center-to-limb variation of the plasma speed and loop geometry of chromospheric superpenumbral fibrils in eleven sunspots that were located at a wide range of heliocentric angles from 12 to 79 deg. The observations were acquired at the Dunn Solar Telescope in the spectral lines of Halpha at 656nm, CaII IR at 854 nm and HeI at 1083 nm. All sunspots display opposite line-of-sight (LOS) velocities on the limb and center side with a distinctRead More →

The growth factor parametrization versus numerical solutions in flat and non-flat dark energy models. (arXiv:2008.12741v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Velasquez_Toribio_A/0/1/0/all/0/1">A. M. Vel&#xe1;squez-Toribio</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fabris_J/0/1/0/all/0/1">J&#xfa;lio C. Fabris</a> In the present investigation we use observational data of $ f sigma_ {8} $ to determine observational constraints in the plane $(Omega_{m0},sigma_{8})$ using two different methods: the growth factor parametrization and the numerical solutions method for density contrast, $delta_{m}$. We verified the correspondence between both methods for three models of accelerated expansion: the $Lambda CDM$ model, the $ w_{0}w_{a} CDM$ model and the running cosmological constant $RCC$ model. In all case we consider also curvature as free parameter. The study ofRead More →

Decoding Dark Matter Substructure without Supervision. (arXiv:2008.12731v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Alexander_S/0/1/0/all/0/1">Stephon Alexander</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gleyzer_S/0/1/0/all/0/1">Sergei Gleyzer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Parul_H/0/1/0/all/0/1">Hanna Parul</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Reddy_P/0/1/0/all/0/1">Pranath Reddy</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Toomey_M/0/1/0/all/0/1">Michael W. Toomey</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Usai_E/0/1/0/all/0/1">Emanuele Usai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Klar_R/0/1/0/all/0/1">Ryker Von Klar</a> The identity of dark matter remains one of the most pressing questions in physics today. While many promising dark matter candidates have been put forth over the last half-century, to date the true identity of dark matter remains elusive. While it is possible that one of the many proposed candidates may turn out to be dark matter, it is at least equally likely that the correct physical description has yet to be proposed. ToRead More →

QUBIC VII: The feedhorn-switch system of the technological demonstrator. (arXiv:2008.12721v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Cavaliere_F/0/1/0/all/0/1">F. Cavaliere</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mennella_A/0/1/0/all/0/1">A. Mennella</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zannoni_M/0/1/0/all/0/1">M. Zannoni</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Battaglia_P/0/1/0/all/0/1">P. Battaglia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Battistelli_E/0/1/0/all/0/1">E.S. Battistelli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Burke_D/0/1/0/all/0/1">D. Burke</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+DAlessandro_G/0/1/0/all/0/1">G. D&#x27;Alessandro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bernardis_P/0/1/0/all/0/1">P. de Bernardis</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Petris_M/0/1/0/all/0/1">M. De Petris</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Franceschet_C/0/1/0/all/0/1">C. Franceschet</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Grandsire_L/0/1/0/all/0/1">L. Grandsire</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hamilton_J/0/1/0/all/0/1">J.-Ch. Hamilton</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Maffei_B/0/1/0/all/0/1">B. Maffei</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Manzan_E/0/1/0/all/0/1">E. Manzan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Marnieros_S/0/1/0/all/0/1">S. Marnieros</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Masi_S/0/1/0/all/0/1">S. Masi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+OSullivan_C/0/1/0/all/0/1">C. O&#x27;Sullivan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Passerini_A/0/1/0/all/0/1">A. Passerini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Pezzotta_F/0/1/0/all/0/1">F. Pezzotta</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Piat_M/0/1/0/all/0/1">M. Piat</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tartari_A/0/1/0/all/0/1">A. Tartari</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Torchinsky_S/0/1/0/all/0/1">S.A. Torchinsky</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vigano_D/0/1/0/all/0/1">D. Vigan&#xf2;</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Voisin_F/0/1/0/all/0/1">F. Voisin</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ade_P/0/1/0/all/0/1">P. Ade</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Alberro_J/0/1/0/all/0/1">J.G. Alberro</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Almela_A/0/1/0/all/0/1">A. Almela</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Amico_G/0/1/0/all/0/1">G. Amico</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Arnaldi_L/0/1/0/all/0/1">L.H. Arnaldi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Auguste_D/0/1/0/all/0/1">D. Auguste</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Aumont_J/0/1/0/all/0/1">J.Read More →

Primordial gravitational waves spectrum in the interacting Bose-Einstein gas model. (arXiv:2008.12701v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Izquierdo_G/0/1/0/all/0/1">German Izquierdo</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Alonzo_G/0/1/0/all/0/1">Gildardo Alonzo</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Besprosvany_J/0/1/0/all/0/1">Jaime Besprosvany</a> We study the evolution and power spectrum of primordial gravitational waves in the interactive Bose-Einstein gas model for dark energy, relevant, as it addresses the coincidence problem. The model is applied in the radiation, matter and dark-energy domination stages. The model introduces a scale factor associated with the radiation-matter transition which influences the gravitational spectrum. We focus on the impact of the free parameters on both the gravitational waves amplitude and its power-spectrum slope. For sets of parameters fitting Hubble’s law, we show thatRead More →

Pearson cross-correlation in the first four black hole binary mergers. (arXiv:2008.12663v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Marcoccia_P/0/1/0/all/0/1">Paolo Marcoccia</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Fredriksson_F/0/1/0/all/0/1">Felicia Fredriksson</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Nielsen_A/0/1/0/all/0/1">Alex B. Nielsen</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Nardini_G/0/1/0/all/0/1">Germano Nardini</a> We adopt the Pearson cross-correlation measure to analyze the LIGO Hanford and LIGO Livingston detector data streams around the events GW150914, GW151012,GW151226 and GW170104. We find that the Pearson cross-correlation method is sensitiveto these signals, with correlations peaking when the black hole binaries reconstructed by theLIGO Scientific and Virgo Collaborations, are merging. We compare the obtained cross-correlations with the statistical correlation fluctuations arising in simulated Gaussian noisedata and in LIGO data at times when no event is claimed. Our resultsRead More →

The mass gap, the spin gap, and the origin of merging binary black holes. (arXiv:2004.00650v2 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Baibhav_V/0/1/0/all/0/1">Vishal Baibhav</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gerosa_D/0/1/0/all/0/1">Davide Gerosa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Berti_E/0/1/0/all/0/1">Emanuele Berti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wong_K/0/1/0/all/0/1">Kaze W. K. Wong</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Helfer_T/0/1/0/all/0/1">Thomas Helfer</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mould_M/0/1/0/all/0/1">Matthew Mould</a> Two of the dominant channels to produce the black-hole binary mergers observed by LIGO and Virgo are believed to be the isolated evolution of stellar binaries in the field and dynamical formation in star clusters. Their relative efficiency can be characterized by a “mixing fraction.” Pair instabilities prevent stellar collapse from generating black holes more massive than about $45 M_odot$. This “mass gap” only applies to the fieldRead More →

Very long baseline astrometry of PSR J1012+5307 and its implications on alternative theories of gravity. (arXiv:2004.14668v2 [astro-ph.HE] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Ding_H/0/1/0/all/0/1">Hao Ding</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Deller_A/0/1/0/all/0/1">Adam T. Deller</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Freire_P/0/1/0/all/0/1">Paulo Freire</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kaplan_D/0/1/0/all/0/1">David L. Kaplan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lazio_T/0/1/0/all/0/1">T. Joseph W. Lazio</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shannon_R/0/1/0/all/0/1">Ryan Shannon</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Stappers_B/0/1/0/all/0/1">Benjamin Stappers</a> PSR J1012+5307, a millisecond pulsar in orbit with a helium white dwarf (WD), has been timed with high precision for about 25 years. One of the main objectives of this long-term timing is to use the large asymmetry in gravitational binding energy between the neutron star and the WD to test gravitational theories. Such tests, however, will be eventually limited by theRead More →

LOFAR early-time search for coherent radio emission from Short GRB 181123B. (arXiv:2008.12657v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Rowlinson_A/0/1/0/all/0/1">A. Rowlinson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Starling_R/0/1/0/all/0/1">R.L.C. Starling</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gourdji_K/0/1/0/all/0/1">K. Gourdji</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Anderson_G/0/1/0/all/0/1">G.E. Anderson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Veen_S/0/1/0/all/0/1">S. ter Veen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mandhai_S/0/1/0/all/0/1">S. Mandhai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wijers_R/0/1/0/all/0/1">R.A.M.J. Wijers</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shimwell_T/0/1/0/all/0/1">T.W. Shimwell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Horst_A/0/1/0/all/0/1">A.J. van der Horst</a> The mergers of two neutron stars are typically accompanied by broad-band electromagnetic emission from either a relativistic jet or a kilonova. It has also been long predicted that coherent radio emission will occur during the merger phase or from a newly formed neutron star remnant, however this emission has not been seen to date. This paper presents the deepest limits for thisRead More →

Inelastic Dark Matter Electron Scattering and the XENON1T Excess. (arXiv:2006.11938v3 [hep-ph] UPDATED) <a href="http://arxiv.org/find/hep-ph/1/au:+Harigaya_K/0/1/0/all/0/1">Keisuke Harigaya</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Nakai_Y/0/1/0/all/0/1">Yuichiro Nakai</a>, <a href="http://arxiv.org/find/hep-ph/1/au:+Suzuki_M/0/1/0/all/0/1">Motoo Suzuki</a> Detection of electron recoils by dark matter (DM) may reveal the structure of the dark sector. We consider a scenario where a heavier DM particle inelastically scatters off an electron and is converted into a lighter DM particle. A small mass difference between the two DM particles is transferred into electron recoil energy. We investigate the DM-electron interaction mediated by a massive dark photon and evaluate the inelastic DM scattering rate, taking account of the atomic structure. It is found that the scattering rateRead More →

OVI Traces Photoionized Streams With Collisionally Ionized Boundaries in Cosmological Simulations of $z sim 1$ Massive Galaxies. (arXiv:2008.11863v2 [astro-ph.GA] UPDATED) <a href="http://arxiv.org/find/astro-ph/1/au:+Strawn_C/0/1/0/all/0/1">Clayton Strawn</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Roca_Fabrega_S/0/1/0/all/0/1">Santi Roca-F&#xe0;brega</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mandelker_N/0/1/0/all/0/1">Nir Mandelker</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Primack_J/0/1/0/all/0/1">Joel Primack</a>, <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:+Ceverino_D/0/1/0/all/0/1">Daniel Ceverino</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dekel_A/0/1/0/all/0/1">Avishai Dekel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Wang_B/0/1/0/all/0/1">Bryan Wang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dange_R/0/1/0/all/0/1">Rishi Dange</a> We analyse the distribution and origin of OVI in the Circumgalactic Medium (CGM) of dark-matter haloes of $sim 10^{12}$ M$_odot$ at $zsim1$ in the VELA cosmological zoom-in simulations. We find that the OVI in the inflowing cold streams is primarily photoionized, while in the bulk volume it is primarily collisionally ionized. The photoionized component dominates the observed columnRead More →