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Related papers: Hourly radio variability of PDS70c from time-diffe…

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PDS 70c is a source of Ha emission and variable sub-mm signal. Understanding its emission mechanisms may enable observations of accretion rates and physical conditions in the circum-planetary environment. We report ALMA observations of PDS…

The compact mm-wavelength signal in the central cavity of the PDS70 disc, revealed by deep ALMA observations, is aligned with unresolved Halpha emission, and is thought to stem from a circum-planetary disc (CPD) around PDS70c. We revisit…

Earth and Planetary Astrophysics · Physics 2022-06-08 Simon Casassus , Miguel Carcamo

Understanding the processes of planet formation and accretion in young systems is essential to unraveling the initial conditions of planetary systems. The PDS 70 system, which hosts two directly imaged protoplanets, provides a unique…

The two giant protoplanets directly imaged in the dust-depleted cavity of PDS 70 offer a unique opportunity to study ongoing planet formation. Both planets have been detected in infrared thermal emission and in H$\alpha$, indicating active…

We report 4 years of observations of 3C273 at 7 mm obtained with the Itapetinga Radiotelescope, in Brazil, between 2009 and 2013. We detected a flare in 2010 March, when the flux density increased by 50% and reached 35 Jy. After the flare,…

High Energy Astrophysical Phenomena · Physics 2013-10-09 Pedro Paulo B. Beaklini , Zulema Abraham

We report a new evaluation of the accretion properties of PDS~70b obtained with VLT/MUSE. The main difference from previous studies in Haffert et al. (2019) and Aoyama & Ikoma (2019) is in the mass accretion rate. Simultaneous multiple line…

Earth and Planetary Astrophysics · Physics 2020-05-06 Jun Hashimoto , Yuhiko Aoyama , Mihoko Konishi , Taichi Uyama , Shinsuke Takasao , Masahiro Ikoma , Takayuki Tanigawa

PDS~70 is a protoplanetary system that hosts two actively accreting gas giants, namely PDS~70b and PDS~70c. The system has a $\sim$60--100 au dusty ring that has been resolved by ALMA, along with circumplanetary disks around the two gas…

Earth and Planetary Astrophysics · Physics 2024-07-01 Hauyu Baobab Liu , Simon Casassus , Ruobing Dong , Kiyoaki Doi , Jun Hashimoto , Takayuki Muto

We present the results of a 25-year program to monitor the radio flux evolution of the planetary nebula NGC7027. We find significant evolution of the spectral flux densities. The flux density at 1465 MHz, where the nebula is optically…

Astrophysics · Physics 2009-11-13 Albert Zijlstra , P. A. M. van Hoof , R. A. Perley

The circumstellar disk of PDS 70 hosts two forming planets, which are actively accreting gas from their environment. In this work, we report the first detection of PDS 70 b in the Br$\alpha$ and $M'$ filters with VLT/NACO, a tentative…

Earth and Planetary Astrophysics · Physics 2021-01-04 Tomas Stolker , Gabriel-Dominique Marleau , Gabriele Cugno , Paul Mollière , Sascha P. Quanz , Kamen O. Todorov , Jonas Kühn

We present new measurements of the diffuse radio halo emission from the Coma cluster of galaxies at 2.675 GHz and 4.85 GHz using the Effelsberg 100--m telescope. After correction for the contribution from point sources we derive the…

Astrophysics · Physics 2011-07-18 M. Thierbach , U. Klein , R. Wielebinski

We monitored 13 moderate luminosity active galactic nuclei at z=0.36 to measure flux variability, explore feasibility of reverberation mapping, and determine uncertainties on estimating black hole mass from single-epoch data. Spectra and…

Astrophysics · Physics 2011-02-11 J. -H. Woo , T. Treu , M. A. Malkan , M. A. Ferry , T. Misch

The PDS 70 system, hosting two planets within its disk, is an ideal target for examining the effect of planets on dust accumulation, growth, and ongoing planet formation. Here, we present high-resolution ($0.''07 = 8 \ \mathrm{au}$) dust…

Earth and Planetary Astrophysics · Physics 2024-09-26 Kiyoaki Doi , Akimasa Kataoka , Hauyu Baobab Liu , Tomohiro C. Yoshida , Myriam Benisty , Ruobing Dong , Yoshihide Yamato , Jun Hashimoto

Multi-wavelength simultaneous observations are essential to the constraints on the origin of fast radio bursts (FRBs). However, it is a significant observational challenge due to the nature of FRBs as transients with a radio millisecond…

We present a study of the flux and spectral variability of the two broad-line radio galaxies (BLRGs) 3C 390.3 and 3C 120, observed almost daily with RXTE for nearly two months each in 1996 and 1997, respectively. Our original motivation for…

Astrophysics · Physics 2009-11-07 M. Gliozzi , R. M. Sambruna , M. Eracleous

Variability of pre-main-sequence stars observed at optical wavelengths has been attributed tofluctuations in the mass accretion rate from the circumstellar disk onto the forming star.Detailed models of accretion disks suggest that young…

Solar and Stellar Astrophysics · Physics 2019-02-05 Logan Francis , Doug Johnstone , Michael M. Dunham , Todd R. Hunter , Steve Mairs

We present some first results on the variability, polarization and general properties of radio sources selected in a blind survey at 20 GHz, the highest frequency at which a sensitive radio survey has been carried out over a large area of…

With two directly detected protoplanets, the PDS 70 system is a unique source in which to study the complex interplay between forming planets and their natal environment. The large dust cavity carved by the two giant planets can affect the…

Earth and Planetary Astrophysics · Physics 2024-09-04 L. Rampinelli , S. Facchini , M. Leemker , J. Bae , M. Benisty , R. Teague , C. J. Law , K. I. Öberg , B. Portilla-Revelo , A. J. Cridland

The Parkes telescope has been monitoring 286 radio pulsars approximately monthly since 2007 at an observing frequency of 1.4 GHz. The wide dispersion measure (DM) range of the pulsar sample and the uniformity of the observing procedure make…

High Energy Astrophysical Phenomena · Physics 2021-01-06 H. Kumamoto , S. Dai , S. Johnston , M. Kerr , R. M. Shannon , P. Weltevrede , C. Sobey , R. N. Manchester , G. Hobbs , K. Takahashi

Recent observations of protoplanets embedded in circumstellar disks have shed light on the planet formation process. In particular, detection of hydrogen Balmer-line (H{\alpha}) emission gives direct constraints on late-stage accretion onto…

Earth and Planetary Astrophysics · Physics 2021-08-04 Yuhiko Aoyama , Masahiro Ikoma

The Planck mission detected thousands of extragalactic radio sources at frequencies from 28 to 857 GHz. Planck's calibration is absolute (in the sense that it is based on the satellite's annual motion around the Sun and the temperature of…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-27 B. Partridge , M. López-Caniego , R. A. Perley , J. Stevens , B. J. Butler , G. Rocha , B. Walter , A. Zacchei
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