RAS_WEB (Page 3,784)

Study of the performance of an array of Cherenkov telescopes by means of multi-objective evolutionary optimisation. (arXiv:1907.12041v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Souto_B/0/1/0/all/0/1">Bruno Fontes Souto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Almeida_U/0/1/0/all/0/1">Ulisses Barres de Almeida</a> This paper is concerned with the performance optimisation of an stereoscopic array of imaging atmospheric Cherenkov telescopes (IACTs) as a function of their positioning on the ground. In this first work we are concerned primarily with the study of the optimisation method and its test on toy arrays of few (3-6) telescopes. The ideas presented here were developed to investigate alternative ways of studying IACT array geometries. The proposal is an attempt to cover more exhaustively and systematicallyRead More →

The 2018 eruption and long term evolution of the new high-mass Herbig Ae/Be object Gaia-18azl = VES 263. (arXiv:1907.12050v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Munari_U/0/1/0/all/0/1">U. Munari</a> (INAF Padova), <a href="http://arxiv.org/find/astro-ph/1/au:+Joshi_V/0/1/0/all/0/1">V. Joshi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Banerjee_D/0/1/0/all/0/1">D.P.K. Banerjee</a> (Physical Research Lab., Ahmedabad), <a href="http://arxiv.org/find/astro-ph/1/au:+Cotar_K/0/1/0/all/0/1">K. Cotar</a> (Univ. Ljubljana), <a href="http://arxiv.org/find/astro-ph/1/au:+Y%2E_S/0/1/0/all/0/1">Shugarov S.Y.</a> (Sternberg Astron. Inst.), <a href="http://arxiv.org/find/astro-ph/1/au:+Jurdana_Sepic_R/0/1/0/all/0/1">R. Jurdana-Sepic</a> (Univ. Rijeka), <a href="http://arxiv.org/find/astro-ph/1/au:+Belligoli_R/0/1/0/all/0/1">R. Belligoli</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bergamini_A/0/1/0/all/0/1">A. Bergamini</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Graziani_M/0/1/0/all/0/1">M. Graziani</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Righetti_G/0/1/0/all/0/1">G.L. Righetti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Vagnozzi_A/0/1/0/all/0/1">A. Vagnozzi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Valisa_P/0/1/0/all/0/1">P. Valisa</a> (ANS Collaboration) We have been monitoring, at high cadence, the photometric and spectroscopic evolution of VES 263 following the discovery in 2018 of a brightening labeled as event Gaia-18azl. VES 263 is so far a neglectedRead More →

Polarization of the Cosmic Infrared Background Fluctuations. (arXiv:1907.12085v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Feng_C/0/1/0/all/0/1">Chang Feng</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Holder_G/0/1/0/all/0/1">Gilbert Holder</a> The cosmic infrared background (CIB) is slightly polarized. Polarization directions of individual galaxies could be aligned with tidal fields around galaxies, resulting in nonzero CIB polarization. We use a linear intrinsic alignment model to theoretically predict angular correlations of the CIB polarization fluctuations and find that electriclike and curl-like ($B$-mode) polarization modes are equally generated with power four orders of magnitude less than its intensity. The CIB $B$-mode signal is negligible and not a concerning foreground for the inflationary $B$-mode searches at nominal frequencies for cosmic microwave background measurements, butRead More →

Parametric-resonance based phenomenology of gravitating axion configurations. (arXiv:1907.12089v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Boskovic_M/0/1/0/all/0/1">Mateja Bo&#x161;kovi&#x107;</a> One of the most compelling candidates for Dark Matter (DM) are light pseudo-scalar particles (axions), motivated by the strong CP problem and axiverse scenario in string theory. Depending on their mass and type of self-interaction, these particles can build self-gravitating configurations such as compact objects, DM clumps or even galactic DM halos. On the other hand, superradiant instabilities can produce long-living extended configurations (scalar clouds) gravitating around Black Holes (BHs). As these scalars are real and harmonic, their interaction with the other matter components can induce a parametric resonance that might lead toRead More →

Conflicting disk inclination estimates for the black hole X-ray binary XTE J1550-564. (arXiv:1907.12114v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Connors_R/0/1/0/all/0/1">Riley~M.~T.~Connors</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Garcia_J/0/1/0/all/0/1">Javier~A.~Garcia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Steiner_J/0/1/0/all/0/1">James~F.~Steiner</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Grinberg_V/0/1/0/all/0/1">Victoria Grinberg</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dauser_T/0/1/0/all/0/1">Thomas Dauser</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Sridhar_N/0/1/0/all/0/1">Navin Sridhar</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gatuzz_E/0/1/0/all/0/1">Efrain Gatuzz</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tomsick_J/0/1/0/all/0/1">John Tomsick</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Markoff_S/0/1/0/all/0/1">Sera B. Markoff</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Harrison_F/0/1/0/all/0/1">Fiona Harrison</a> XTE J1550-564 is a black hole X-ray binary for which the dynamical characteristics are well established, and the broadband spectral evolution of the source has been well studied. Its orbital inclination is known to be high, at $sim75^{circ}$, with the jet estimated to align well with the orbital axis. We explore simultaneous observations made with ASCA and RXTE, covering the $1$–$200$~keV band, duringRead More →

On the TeV Halo Fraction in gamma-ray bright Pulsar Wind Nebulae. (arXiv:1907.12121v1 [astro-ph.HE]) <a href="http://arxiv.org/find/astro-ph/1/au:+Giacinti_G/0/1/0/all/0/1">G. Giacinti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Mitchell_A/0/1/0/all/0/1">A. M. W. Mitchell</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Lopez_Coto_R/0/1/0/all/0/1">R. L&#xf3;pez-Coto</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Joshi_V/0/1/0/all/0/1">V. Joshi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Parsons_R/0/1/0/all/0/1">R. D. Parsons</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Hinton_J/0/1/0/all/0/1">J. A. Hinton</a> The discovery of extended TeV emission around the Geminga and PSR B0656+14 pulsars, with properties consistent with free particle propagation in the interstellar medium (ISM), has sparked considerable discussion on the possible presence of such halos in other systems. Here we make an assessment of the current TeV source population associated with energetic pulsars, in terms of size and estimated energy density. Based on two alternative estimators we conclude thatRead More →

Impact of $1/f$ noise on cosmological parameter constraints for SKA intensity mapping. (arXiv:1907.12132v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_T/0/1/0/all/0/1">T.Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Battye_R/0/1/0/all/0/1">R.A.Battye</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Costa_A/0/1/0/all/0/1">A.A.Costa</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Dickinson_C/0/1/0/all/0/1">C.Dickinson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Harper_S/0/1/0/all/0/1">S.E.Harper</a> We investigate the impact of $1/f$ noise on cosmology for an intensity mapping survey with SKA1-MID Band,1 and Band,2. We use a Fisher matrix approach to forecast constraints on cosmological parameters under the influence of $1/f$ noise, adopting a semi-empirical model from an earlier work, which results from the residual $1/f$ noise spectrum after applying a component separation algorithm to remove smooth spectral components. Without $1/f$ noise, the projected constraints are $4%$ on $w_0$, $1%$ on $h$, $2%$ on $b_{rm HI}$Read More →

A contribution of star-forming clumps and accreting satellites to the mass assembly of z ~ 2 galaxies. (arXiv:1907.12136v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Zanella_A/0/1/0/all/0/1">A. Zanella</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Floch_E/0/1/0/all/0/1">E. Le Floc&#x27;h</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Harrison_C/0/1/0/all/0/1">C. M. Harrison</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Daddi_E/0/1/0/all/0/1">E. Daddi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bernhard_E/0/1/0/all/0/1">E. Bernhard</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Gobat_R/0/1/0/all/0/1">R. Gobat</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Strazzullo_V/0/1/0/all/0/1">V. Strazzullo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Valentino_F/0/1/0/all/0/1">F. Valentino</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cibinel_A/0/1/0/all/0/1">A. Cibinel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Almeida_J/0/1/0/all/0/1">J. S&#xe1;nchez Almeida</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kohandel_M/0/1/0/all/0/1">M. Kohandel</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Fensch_J/0/1/0/all/0/1">J. Fensch</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Behrendt_M/0/1/0/all/0/1">M. Behrendt</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Burkert_A/0/1/0/all/0/1">A. Burkert</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Onodera_M/0/1/0/all/0/1">M. Onodera</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Bournaud_F/0/1/0/all/0/1">F. Bournaud</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Scholtz_J/0/1/0/all/0/1">J. Scholtz</a> We investigate the contribution of clumps and satellites to the galaxy mass assembly. We analyzed spatially-resolved Hubble Space Telescope observations (imaging and slitless spectroscopy) of 53 star-forming galaxies at z ~ 1Read More →

Solar Image Restoration with the Cycle-GAN Based on Multi-Fractal Properties of Texture Features. (arXiv:1907.12192v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Jia_P/0/1/0/all/0/1">Peng Jia</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Huang_Y/0/1/0/all/0/1">Yi Huang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cai_B/0/1/0/all/0/1">Bojun Cai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cai_D/0/1/0/all/0/1">Dongmei Cai</a> Texture is one of the most obvious characteristics in solar images and it is normally described by texture features. Because textures from solar images of the same wavelength are similar, we assume texture features of solar images are multi-fractals. Based on this assumption, we propose a pure data-based image restoration method: with several high resolution solar images as references, we use the Cycle-Consistent Adversarial Network to restore burred images of the same steady physical process, in the sameRead More →

Coupled vector dark energy. (arXiv:1907.12216v1 [gr-qc]) <a href="http://arxiv.org/find/gr-qc/1/au:+Nakamura_S/0/1/0/all/0/1">Shintaro Nakamura</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Kase_R/0/1/0/all/0/1">Ryotaro Kase</a>, <a href="http://arxiv.org/find/gr-qc/1/au:+Tsujikawa_S/0/1/0/all/0/1">Shinji Tsujikawa</a> We provide a general framework for studying the evolution of background and cosmological perturbations in the presence of a vector field $A_{mu}$ coupled to cold dark matter (CDM). We consider an interacting Lagrangian of the form $Q f(X) T_c$, where $Q$ is a coupling constant, $f$ is an arbitrary function of $X=-A_{mu}A^{mu}/2$, and $T_c$ is a trace of the CDM energy-momentum tensor. The matter coupling affects the no-ghost condition and sound speed of longitudinal scalar perturbation in the small-scale limit, while those of tensor and vector perturbations are not subjectRead More →

New test on General Relativity using galaxy-galaxy lensing with astronomical surveys. (arXiv:1907.12225v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_Z/0/1/0/all/0/1">Zhaoting Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Luo_W/0/1/0/all/0/1">Wentao Luo</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Cai_Y/0/1/0/all/0/1">Yi-Fu Cai</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Saridakis_E/0/1/0/all/0/1">Emmanuel N. Saridakis</a> We use data from galaxy-galaxy weak lensing to perform a novel test on General Relativity (GR). In particular, we impose strong constraints using the torsional (teleparallel) formulation of gravity in which the deviation from GR is quantified by a single parameter $alpha$, an approximation which is always valid at low-redshift Universe and weak gravitational fields. We calculate the difference in the deflection angle and eventually derive the modified Excess Surface Density profile, which is mainly affected at small scales.Read More →

Turbulence and Rotation in Solar-Type Stars. (arXiv:1907.12241v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+A_S/0/1/0/all/0/1">Sheminova V. A</a> Stellar spectra with a high resolution of 115000 obtained with the HARPS spectrograph provide an opportunity to examine turbulence velocities and their depth distributions in the photosphere of stars. Fourier analysis was performed for 17 iron lines in the spectra of 13 stars with an effective temperature of 4900–6200 K and a logarithm of surface gravity of 3.9–5.0 as well as in the spectrum of the Sun as a star. Models of stellar atmospheres were taken from the MARCS database. The standard concept of isotropic Gaussian microturbulence was assumed in this study. ARead More →

The 50-100pc scale parent stellar populations of type II supernovae and limitations of single star evolution models. (arXiv:1907.12260v1 [astro-ph.SR]) <a href="http://arxiv.org/find/astro-ph/1/au:+Schady_P/0/1/0/all/0/1">P. Schady</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Eldridge_J/0/1/0/all/0/1">J.J. Eldridge</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Anderson_J/0/1/0/all/0/1">J. Anderson</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chen_T/0/1/0/all/0/1">T.-W. Chen</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Galbany_L/0/1/0/all/0/1">L. Galbany</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kuncarayakti_H/0/1/0/all/0/1">H. Kuncarayakti</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Xiao_L/0/1/0/all/0/1">L. Xiao</a> There is observational evidence of a dearth in core-collapse supernova (ccSN) explosions from stars with zero age main sequence (ZAMS) mass M_0~17-30 Msolar, referred to as the `red supergiant problem’. However, simulations now predict that above 20 Msolar, we should indeed only expect stars within certain pockets of M_0 to produce a visible SN explosion. Validating these predictions requires large numbers of ccSNe of differentRead More →

A far Ultra-Violet Polarimeter by reflection for Pollux on board LUVOIR. (arXiv:1907.12281v1 [astro-ph.IM]) <a href="http://arxiv.org/find/astro-ph/1/au:+Gal_M/0/1/0/all/0/1">Maelle Le Gal</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Ariste_A/0/1/0/all/0/1">Arturo Lopez Ariste</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Neiner_C/0/1/0/all/0/1">Coralie Neiner</a> The ultra-violet (UV) high-resolution spectropolarimeter Pollux is being studied in Europe under CNES leadership for the LUVOIR space mission. LUVOIR is a projected 15-m telescope equipped with a suite of instruments proposed to NASA. Pollux will perform spectropolarimetric measurements from 90 to 400 nm with a resolution of 120000. The spectrograph will be divided in three channels, each with its own polarimeter: far UV (FUV, 90-124.5 nm), mid UV (MUV, 118.5-195 nm), and near UV (NUV, 190-390 nm). We present hereRead More →

Ruling out the supersoft high-density symmetry energy from the discovery of PSR J0740+6620 with mass $2.17^{+0.11}_{-0.10}M_odot$. (arXiv:1907.12284v1 [nucl-th]) <a href="http://arxiv.org/find/nucl-th/1/au:+Zhou_Y/0/1/0/all/0/1">Ying Zhou</a>, <a href="http://arxiv.org/find/nucl-th/1/au:+Chen_L/0/1/0/all/0/1">Lie-Wen Chen</a> Using the very recently reported mass $2.17^{+0.11}_{-0.10}M_odot$ of PSR J0740+6620 together with the data of finite nuclei and the constraints on the equation of state of symmetric nuclear matter at suprasaturation densities from flow data in heavy-ion collisions, we show that the symmetry energy $E_{rm sym}(n)$ cannot be supersoft so that it becomes negative at suprasaturation densities in neutron stars (NSs) and thus may make the NS have a pure neutron matter core. This is in contrast to the fact thatRead More →

Testing for gravitational preferred directions with galaxy and lensing surveys. (arXiv:1907.12285v1 [astro-ph.CO]) <a href="http://arxiv.org/find/astro-ph/1/au:+Resco_M/0/1/0/all/0/1">Miguel Aparicio Resco</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Maroto_A/0/1/0/all/0/1">Antonio L. Maroto</a> We analyze the sensitivity of galaxy and weak-lensing surveys to detect preferred directions in the gravitational interaction. We consider general theories of gravity involving additional vector degrees of freedom with non-vanishing spatial components in the background. We use a model-independent parametrization of the perturbations equations in terms of four effective parameters, namely, the standard effective Newton constant $G_{eff}$ and slip parameter $gamma$ for scalar modes and two new parameters $mu_Q$ and $mu_h$ for vector and tensor modes respectively, which are required when preferred directions areRead More →

Role of matter in gravitation: going beyond the Einstein-Maxwell theory. (arXiv:1907.12292v1 [hep-th]) <a href="http://arxiv.org/find/hep-th/1/au:+Gumrukcuoglu_A/0/1/0/all/0/1">A. Emir Gumrukcuoglu</a>, <a href="http://arxiv.org/find/hep-th/1/au:+Namba_R/0/1/0/all/0/1">Ryo Namba</a> For field theories in curved spacetime, defining how matter gravitates is part of the theory building process. In this letter, we adopt Bekenstein’s multiple geometries approach to allow part of the matter sector to follow the geodesics on a general pseudo-Riemannian geometry, constructed from a tensor and a $U(1)$ gauge field. This procedure allows us to generate a previously unknown corner of vector-tensor theories. In the Jordan frame, apparent high-derivative terms of the vector field are reduced by integrating out an auxiliary variable, at the costRead More →

The kinematic distances of SNR G16.7+0.1 and G15.9+0.2 by analyzing HI absorption spectra. (arXiv:1907.12295v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Tian_W/0/1/0/all/0/1">W.W. Tian</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhu_H/0/1/0/all/0/1">H. Zhu</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Zhang_M/0/1/0/all/0/1">M.F. Zhang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Chang_H/0/1/0/all/0/1">H.K. Chang</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Shan_S/0/1/0/all/0/1">S.S. Shan</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Leahy_D/0/1/0/all/0/1">D.A. Leahy</a> We build HI absorption spectra towards Supernova Remnant (SNRs) G16.7+0.1 and G15.9+0.2 using the THOR survey data. With the absorption spectra, we give a new distance range of 7 to 16 kpc for G15.9+0.2. We also resolve the near/far-side distance ambiguity of G16,7+0.1 and confirm its kinematic distance of about 14 kpc. In addition, we analyze the CO (J=3-2) spectra towards G16.7+0.1 and find obvious CO emission at the 20 kms$^{-1}$ OHRead More →

Eddington, Lemaitre and the discovery of the expanding universe. (arXiv:1907.12297v1 [physics.hist-ph]) <a href="http://arxiv.org/find/physics/1/au:+ORaifeartaigh_C/0/1/0/all/0/1">Cormac O&#x27;Raifeartaigh</a> One of the leading astronomers and theorists of his generation, Arthur Stanley Eddington was an important early proponent of the general theory of relativity in both theory and experiment. Yet when his former student Georges Lemaitre suggested in 1927 that the well-known redshifts of the spiral nebulae could be explained in terms of a relativistic expansion of space, Eddington paid no attention for three years. In this paper, we consider the reasons Lemaitre’s hypothesis attracted little attention when it was first articulated. We review several factors that have previously been discussedRead More →

Rotating Ionized Gas Ring around the Galactic Center IRS13E3. (arXiv:1907.12311v1 [astro-ph.GA]) <a href="http://arxiv.org/find/astro-ph/1/au:+Tsuboi_M/0/1/0/all/0/1">Masato Tsuboi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Kitamura_Y/0/1/0/all/0/1">Yoshimi Kitamura</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Tsutsumi_T/0/1/0/all/0/1">Takahiro Tsutsumi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Miyawaki_R/0/1/0/all/0/1">Ryosuke Miyawaki</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Miyoshi_M/0/1/0/all/0/1">Makoto Miyoshi</a>, <a href="http://arxiv.org/find/astro-ph/1/au:+Miyazaki_A/0/1/0/all/0/1">Atsushi Miyazaki</a> We detected a compact ionized gas associated physically with IRS13E3, an Intermediate Mass Black Hole (IMBH) candidate in the Galactic Center, in the continuum emission at 232 GHz and H30$alpha$ recombination line using ALMA Cy.5 observation (2017.1.00503.S, P.I. M.Tsuboi). The continuum emission image shows that IRS13E3 is surrounded by an oval-like structure. The angular size is $0″.093pm0″.006times 0″.061pm0″.004$ ( $1.14times10^{16}$ cm $times 0.74times10^{16}$ cm). The structure is also identified in the H30$alpha$ recombination line. This isRead More →