Scientific Dissemination of Astronomy at the Observatory Abrahão de Moraes

O Observatório Abrahão de Moraes, com sede no município de Valinhos-SP e acesso por Vinhedo-SP, é um laboratório de pesquisa científica pertencente ao Instituto de Astronomia, Geofísica e Ciências Atmosféricas da Universidade de São Paulo. Graças aos interesses e esforços de professores, alunos e funcionários, ele gradativamente abriu suas portas à divulgação científica, sendo hoje, reconhecidamente, um importante centro de difusão do conhecimento na região, atingindo também cidades mais distantes. Esta difusão se dá através de contatos diretos com o público nas visitações diurnas, bastante frequentes, nas noites de observações regulares, ambas com agendamento prévio e ainda nos eventos esporádicos como Portas abertas e Férias com mais estrelas, além de palestras e estágios. Além disso, tem também um contato indireto bastante intenso, através do uso de um de seus telescópios via internet e de frequentes inserções na mídia, principalmente regional. Desde 2008 são recebidos, em média, mais de 2000 visitantes por ano e pode ser muito mais ainda, desde que tenha infraestrutura material e humana adequadas. O aprimoramento das condições atuais está no horizonte da instituição, vindo de encontro à valorização, cada vez maior, que a USP e outros órgãos financiadores de pesquisa estão dando a essas atividades.The Abrahão de Moraes Observatory, established in the city of Valinhos-SP, and accessed by Vinhedo-SP, is a laboratory of scientific research belonging to the Institute of Astronomy, Geophysics and Atmospheric Sciences of the University of São Paulo. Due to the interests and efforts of professors, students and staff, it gradually opened its doors to scientific dissemination and now is recognized as an important center for dissemination of knowledge in its region, reaching even other farther cities. This diffusion occurs in direct contact through the quite frequently daytime visitations and nights of regular observations, both with prior reservation and even with sporadic events like open doors days, lectures and scholarships. Moreover, the indirect contact with public is also very intense through the use of one of its telescopes via Internet and recurrent insertions in the media, especially regional. Since 2008, are received, on average, more than 2,000 visitors each year, a number that may increase with adequate human and physical infrastructure. The improvement of the current conditions is on the horizon of the institution, encountering the increasing appreciation, which the University and other research funding agencies have been attributing to these activities

A Brief Overview of the Absolute Proper motions Outside the Plane catalog (APOP)

APOP is the first version of an absolute proper motion catalog achieved using the Digitized Sky Survey Schmidt plate material outside the galactic plane (|b|≥ 27(o) ). The resulting global zero point error is less than 0.6 mas/yr, and the precision better than 4.0 mas/yr for objects brighter than R_{F}=18.5, rising to 9.0 mas/yr for objects with magnitude in the range 18.5<R_{F}<20.0. The average position accuracy is about 150 mas (per coordinate) with a systematic deviation from the ICRS around 0.2 mas. The catalog covers 22,525 square degrees and lists 100,777,385 objects to the limiting magnitude of R_{F}̃ 20.8. Although the Gaia mission is poised to set the new standard in catalog astronomy, the methods and procedures used for APOP will be useful in other reductions to dispel astrometric magnitude- and color-dependent systematic errors from the next generation of ground-based surveys

Gaia GraL: Gaia DR2 Gravitational Lens Systems. VII. XMM-Newton Observations of Lensed Quasars

© 2022. The Author(s). Published by the American Astronomical Society. This is the accepted manuscript version of an article which has been published in final form at https://doi.org/10.3847/1538-4357/ac4476We present XMM-Newton X-ray observations of nine confirmed lensed quasars at 1 ≲ z ≲ 3 identified by the Gaia Gravitational Lens program. Eight systems are strongly detected, with 0.3-8.0 keV fluxes F 0.3-8.0 ≳ 5 ×10-14 erg cm-2 s-1. Modeling the X-ray spectra with an absorbed power law, we derive power-law photon indices and 2-10 keV luminosities for the eight detected quasars. In addition to presenting sample properties for larger quasar population studies and for use in planning for future caustic-crossing events, we also identify three quasars of interest: a quasar that shows evidence of flux variability from previous ROSAT observations, the most closely separated individual lensed sources resolved by XMM-Newton, and one of the X-ray brightest quasars known at z > 3. These sources represent the tip of the discoveries that will be enabled by SRG/eROSITA.Peer reviewe

Gaia GraL: Gaia DR2 gravitational lens systems – VIII. A radio census of lensed systems

© 2024 The Author(s). Published by Oxford University Press on behalf of Royal Astronomical Society. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY), https://creativecommons.org/licenses/by/4.0/We present radio observations of 24 confirmed and candidate strongly lensed quasars identified by the Gaia Gravitational Lenses working group. We detect radio emission from eight systems in 5.5 and 9 GHz observations with the Australia Telescope Compact Array (ATCA), and 12 systems in 6 GHz observations with the Karl G. Jansky Very Large Array (VLA). The resolution of our ATCA observations is insufficient to resolve the radio emission into multiple lensed images, but we do detect multiple images from 11 VLA targets. We have analysed these systems using our observations in conjunction with existing optical measurements, including measuring offsets between the radio and optical positions for each image and building updated lens models. These observations significantly expand the existing sample of lensed radio quasars, suggest that most lensed systems are detectable at radio wavelengths with targeted observations, and demonstrate the feasibility of population studies with high-resolution radio imaging.Peer reviewe

Gaia GraL: Gaia DR2 Gravitational Lens Systems. VIII. A radio census of lensed systems

We present radio observations of 24 confirmed and candidate strongly lensed quasars identified by the Gaia Gravitational Lenses (GraL) working group. We detect radio emission from 8 systems in 5.5 and 9 GHz observations with the Australia Telescope Compact Array (ATCA), and 12 systems in 6 GHz observations with the Karl G. Jansky Very Large Array (VLA). The resolution of our ATCA observations is insufficient to resolve the radio emission into multiple lensed images, but we do detect multiple images from 11 VLA targets. We have analysed these systems using our observations in conjunction with existing optical measurements, including measuring offsets between the radio and optical positions, for each image and building updated lens models. These observations significantly expand the existing sample of lensed radio quasars, suggest that most lensed systems are detectable at radio wavelengths with targeted observations, and demonstrate the feasibility of population studies with high resolution radio imaging

The Gould's Belt Distances Survey (GOBELINS). IV. Distance, Depth, and Kinematics of the Taurus Star-forming Region

We present new trigonometric parallaxes and proper motions of young stellar objects in the Taurus molecular cloud complex from observations collected with the Very Long Baseline Array as part of the Gould's Belt Distances Survey. We detected 26 young stellar objects and derived trigonometric parallaxes for 18 stars with an accuracy of 0.3% to a few percent. We modeled the orbits of six binaries and determined the dynamical masses of the individual components in four of these systems (V1023 Tau, T Tau S, V807 Tau, and V1000 Tau). Our results are consistent with the first trigonometric parallaxes delivered by the Gaia satellite and reveal the existence of significant depth effects. We find that the central portion of the dark cloud Lynds 1495 is located at d =129.5 ± 0.3 pc, while the B216 clump in the filamentary structure connected to it is at d = 158.1 ± 1.2 pc. The closest and remotest stars in our sample are located at d = 126.6 ± 1.7 pc and d = 162.7 ± 0.8 pc, yielding a distance difference of about 36 pc. We also provide a new distance estimate for HL Tau that was recently imaged. Finally, we compute the spatial velocity of the stars with published radial velocity and investigate the kinematic properties of the various clouds and gas structures in this region

Gaia GraL: Gaia DR2 Gravitational Lens Systems. VII. XMM-Newton Observations of Lensed Quasars

Abstract We present XMM-Newton X-ray observations of nine confirmed lensed quasars at 1 ≲ z ≲ 3 identified by the Gaia Gravitational Lens program. Eight systems are strongly detected, with 0.3–8.0 keV fluxes F 0.3−8.0 ≳ 5 ×10−14 erg cm−2 s−1. Modeling the X-ray spectra with an absorbed power law, we derive power-law photon indices and 2–10 keV luminosities for the eight detected quasars. In addition to presenting sample properties for larger quasar population studies and for use in planning for future caustic-crossing events, we also identify three quasars of interest: a quasar that shows evidence of flux variability from previous ROSAT observations, the most closely separated individual lensed sources resolved by XMM-Newton, and one of the X-ray brightest quasars known at z &gt; 3. These sources represent the tip of the discoveries that will be enabled by SRG/eROSITA.</jats:p

Traitement global des observations meridiennes de l'Observatoire de Bordeaux

SIGLEINIST T 75685 / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc