2-6 September 2024
CJD Bonn Castell
Europe/Berlin timezone
- evn2024@mpifr.de
Support
Poster Session
Place
Location: CJD Bonn Castell
Address: Graurheindorfer Str. 149, 53117 Bonn
Date:
from 2 Sep 13:30 to 3 Sep 14:00
Contribution List
Displaying 49
contributions
out of
49
Session:
Poster Session
We present the result of the angular diameter distance measurements for a blazar TXS 0506+056 ($z=0.3365$), a radio-bright active galactic nucleus (AGN) whose jet is aligned with the line of sight.
We used the 15 GHz Owens Valley Radio Observatory (OVRO) 40 m single dish (SD) data from MJD 54474 to MJD 59023 (12 years) and the 15 GHz Very Long Baseline Array (VLBA) data from MJD 54838 to MJD 6012
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Presented by Mr. Chanwoo SONG
Session:
Poster Session
GMVA observations are accompanied by a lot of metadata (e.g., so-called `ANTAB` files) which include system temperature (Tsys), antenna gain, and weather information (WX) for each of all those participated GMVA stations. They are required for amplitude calibration of GMVA data which is an essential part in the data calibration. Unfortunately, Tsys measurements almost always have some erroneous val
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Presented by Dr. Daewon KIM
Session:
Poster Session
Spatially-resolved radio observations of the ultracool dwarf (UCD) LSR J1835+3259 have shown extended radio emission consistent with the presence of a steady radiation belt powered by synchrotron emission, and aurora, powered by the coherent electron cyclotron maser mechanism. Those results show that, similar to the Jupiter case, radio emitting UCDs possess dipole-ordered magnetic fields with radi
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Presented by Dr. Juan Bautista CLIMENT
Session:
Poster Session
Very long baseline interferometry (VLBI) observations reveal that active galactic nuclei (AGN) jets often exhibit bending at parsec scales. While individual cases have been studied, broader trends across a large sample remain unclear. We analyse 123,000 multi-frequency VLBI images of 17,000 AGNs. From the total number, we extract 7,927 objects with resolved jet structure, identifying 586 (7% of 7,
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Presented by Mr. Vladislav MAKEEV
Session:
Poster Session
The Automatic Correlation System (ACor) is a web-based platform designed to enhance observation planning, data storage, and processing. It automates scheduling for both single-dish and interferometric modes using the VIRAC radiotelescope complex in Irbene, Latvia, which includes the RT-32, RT-16, and LOFAR radiotelescopes. Key requirements for ACor include open access, web-based functionality, and
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Presented by Mrs. Karina SKIRMANTE
Session:
Poster Session
Active Galactic Nuclei (AGN) form the most abundant class of γ-ray sources. Due to Doppler boosting, the vast majority of these consist of Blazars (viewing angle θ < 8° − 10°), while misaligned (MAGN) sources (θ > 8°−10°) account for a few percent of γ-ray-detected AGN. Despite their low abundance in the γ-ray sky, MAGN are a fundamental tool to study relativistic jets, precisely beca
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Presented by Vieri BARTOLINI
Session:
Poster Session
With my poster, I will show how to use the CASA/rPICARD pipeline (https://bitbucket.org/M_Janssen/picard) for the calibration of VLBI data. The purpose is to introduce new and interested VLBI users to the automated reduction of VLBI data.
I will also present advantages over traditional calibration methods and current rPICARD use cases. Specifically, I will show how to work with publicly available
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Presented by Prof. Michael JANSSEN
Session:
Poster Session
This study explores the benefits of placing a Very Long Baseline Interferometry (VLBI) transmitter
onboard a next-generation Global Navigation Satellite Systems (GNSS) satellite. Classical VLBI to extra-galactic
radio sources is the only space geodetic technique that can determine all five Earth Orientation parameters (EOPs)
in an absolute sense, including UT1-UTC and Celestial Intermediate Pol
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Presented by Prof. Susanne GLASER
Session:
Poster Session
We present an overview of a proposal for the next generation Space VLBI mission Black Hole Explorer (BHEX). Its main scientific goal is to detect the photon ring and measure basic parameters of super-massive black holes in centers of M87 and SgrA*. Other science cases include black hole demographics as well as studying accretion, formation, and collimation of jets in active galaxies. In order to d
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Presented by Prof. Yuri KOVALEV
Session:
Poster Session
In the 2030s, the ESA JUICE and NASA Europa Clipper missions will explore the Jupiter system and provide unprecedented insights into the dynamics of the Galilean satellites. A refined ephemerides estimation will enhance our understanding of their origin and thermal-orbital evolution. However, achieving a robust and consistent solution that matches the low uncertainty levels predicted by current si
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Presented by Dr. Giuseppe CIMO
Session:
Poster Session
The development of the newer version of the VLBI digital front- and back-end system belonging to the DBBC systems’ family is under way as a work-package of the RadioBlocks Project. This instrument dedicated to increase the VLBI observation capabilities in terms of bandwidth and output data rate involves a number of relevant novelties ranging from the full 32 GHz digitized input band in a number
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Presented by Dr. Gino TUCCARI
Session:
Poster Session
The TANAMI program has been using the Southern-hemisphere LBA array and associated telescopes to monitor compact relativistic jets in active galactic nuclei (AGN) at X- and K-band frequencies since 2007 with a focus on bright sources (~1Jy) and synergies with the Fermi gamma-ray space telescope. In preparation for the upcoming era of the Cherenkov Telescope Array (CTA) and to exploit the capabilit
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Presented by Dr. Jompoj WONGPHECHAUXSORN
Session:
Poster Session
The high resolution of Very Long Baseline Interferometry (VLBI) allows us to access dynamic aspects of our Universe. However, the data are typically sparse, and certain sources, such as Sgr A*, can change significantly during observations, making traditional snapshot imaging techniques inadequate.
In this talk, I will present how to use the resolve framework for dynamic imaging of VLBI data. This
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Presented by Dr. Jakob KNOLLMÜLLER
Session:
Poster Session
The 6.7 GHz methanol maser distribution showing a circular morphology in high-mass star-forming regions was discovered 2 decades ago using a sensitive European VLBI Network. Today, after multi-epoch observations, we derive the proper motions of single-masing cloudlets at the level of several kilometres per second. The motions are directed radially outward from the centres of fillet ellipses indica
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Presented by Prof. Anna BARTKIEWICZ
Session:
Poster Session
Relativistic jets from Active Galactic Nuclei (AGN) are suggested to originate from supermassive black holes at the center of galaxies, surrounded by their accretion disks. The properties of the disks are intrinsically linked to the characteristics of the launched jets, in what is known as disk-jet connection. When considering their magnetization, accretion disks fall into two main categories: the
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Presented by Dr. Luca RICCI
Session:
Poster Session
High-redshift quasars provide unique information about the formation and evolution of the first galaxies and supermassive black holes (SMBHs) in the early ~1 billion years old Universe. Powerful relativistic jets, hosted by radio quasars, are thought to have an important role in building up SMBHs for such a short period of time. Thanks to dedicated high-resolution VLBI observations, our knowledge
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Presented by Mr. Máté KREZINGER
Session:
Poster Session
Herbig Ae/Be stars are pre-main-sequence stars that exhibit distinctive visual emission features as well as infrared excess. Both provide valuable information about the physical conditions, kinematics, and composition of the circumstellar material surrounding the Herbig Ae/Be stars.
The high-resolution (R ∼ 30 000) spectra of V700 Mon and LP Ori were obtained using the échelle spectrograph att
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Presented by Dr. Asli ELMASLI
Session:
Poster Session
Radio-loud AGNs with their jets pointed close to our line of sight constitute the majority of extragalactic gamma-ray sources and significantly contribute to the radiation observed in the even higher energy regime. The upcoming Cherenkov Telescope Array (CTA) is expected to detect fainter TeV objects, leading to an anticipated increase in the proportion of non-blazar extragalactic high-energy sour
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Presented by Dr. Krisztina GABANYI
Session:
Poster Session
Flares on the Sun and other stars result from rapid explosive releases of free magnetic energy stored in the solar/stellar coronae. Solar flares and connected with them coronal mass ejections (CME) have a crucial impact on physical conditions in the near-Earth space, known as “space weather”, and on the functioning of various infrastructure facilities such as communication and navigation syste
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Presented by Mr. Vladislavs BEZRUKOVS
Session:
Poster Session
Magnetic fields surrounding black holes are responsible for a variety of astrophysical phenomena related to accretion processes and relativistic jets. Depending on the source, the strength and configuration of the field lines may differ significantly, which can, in turn, affect the trajectories of charged particles and the corresponding observables. Usually, the magnetic fields around black holes
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Presented by Dr. Arman TURSUNOV
Session:
Poster Session
Between December 2023 and April 2024 we conducted a VLBI experiment with LOFAR, NenuFAR, KAIRA and several stations of the LWA to try transatlantic interferometry below 100MHz. Targets were Jupiter (at times of expected decametric bursts) and three bright pulsars. First goal is detecting fringes at all, which was not possible in a smaller experiment more than ten years ago. In the case of success,
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Presented by Olaf WUCKNITZ
Session:
Poster Session
A blazar PKS 0735+178 is a potential candidate for emitting high-energy neutrinos through a relativistic jet. Neutrino observatories (e.g., IceCube, Baikal-GVD, etc.) detected neutrino events with energies ranging from GeV to TeV, from the direction of the source in 2021 December. However, the nature of the neutrinos still needs to be clearly understood. Interestingly, multiwavelength flares have
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Presented by Mr. Sanghyun KIM
Session:
Poster Session
SKA-Low is being constructed in Western Australia and due to become operational in 2027. With a maximum baseline length of 65 Km SKA-Low will be unable to provide high resolution observations on its own, but will have a multi-beam tied array capability allowing it to participate as an element in conventional VLBI arrays. By this means the community will be able to pursue some of the high-sensitivi
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Presented by Dr. Cormac REYNOLDS
Session:
Poster Session
Geodetic and astrometric VLBI has entered a new era with the implementation of the VLBI Global Observing System (VGOS, formerly known as VLBI2010). These broadband and dual linear polarization observations aim at an accuracy of station coordinates of 1 mm and a reference frame scale stability of 0.1 mm/year. Although the extended brightness distribution of many of the radio-loud AGN observed durin
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Presented by Dr. Frederic JARON
Session:
Poster Session
Formation of super-massive black holes binaries (SMBHB) is one of the most challenging problems of theoretical astrophysics, as well as observational astronomy in electromagnetic and gravitational wave domains. A process of inevitable dissipation of kinetic energy in SMBHB controls the evolution of these objects (also referred to as inspiralling or recoiling) and leads toward coalescing into a sin
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Presented by Prof. Leonid GURVITS, Dr. Sándor FREY
Session:
Poster Session
When comparing modern fundamental reference frames in the radio (ICRF) and optical (*Gaia*), a couple of bright radio reference sources appear to have very large radio-optical offsets, from tens up to hundreds of milliarcseconds. The amount of these positional misalignments exceeds the uncertainty of each individual technique by at least an order of magnitude. In most cases, complex and extended r
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Presented by Dr. Sándor FREY
Session:
Poster Session
Blazars, a subclass of radio-loud AGN are among the best laboratories for high-energy astrophysics in the Universe. The relativistic jets in blazars are prominent gamma-ray emitters with rapid variablity down to minute scales. The underlying physical mechanisms and origin of the gamma-ray emission, however, are not yet fully understood. One of the key diagnoses for the relevant studies is to explo
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Presented by Dr. Daewon KIM
Session:
Poster Session
A blazar 3C 454.3 ($z=0.859$) has been extensively investigated in multi-wavelength high-resolution polarization studies, showing polarization variations in milli-arcsecond (mas) scale. We aim to investigate polarimetric characteristics on the blazar 3C 454.3 at 22-129 GHz using decadal (2011-2022) data sets. In addition, we also aim to delve into the origin of the polarization flare in 2019. The
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Presented by Mr. Hyeon-Woo JEONG
Position determination and imaging of bright radio stars by EVN observations using phase-referencing
Session:
Poster Session
Abstract: The VLBI and GAIA observations are on the way to improve the accuracy of celestial reference frame (CRF). Accurate astrometric models of radio stars provide important means to evaluate the consistency between the optical and radio CRFs. This research aims to determine and evaluate the astrometric parameters for the radio stars that have not yet had these parameters determined at radio wa
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Presented by Yertay YESKALI
Session:
Poster Session
The origin of radio emission in radio-quiet (RQ) active galactic nuclei (AGN) has always been controversial. VLBI observation is crucial for studying the inner radio properties of RQ AGNs. We use the EVN to observe five nearby RQ Seyfert galaxies at 1.7 GHz and 5 GHz. These targets were selected from the Swift/BAT AGNs, with selection criteria of compact single-component structures and peak flux d
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Presented by Dr. Ning CHANG
Session:
Poster Session
M81* The third closest Active Galactic Nucleus (AGN), provides a good test for understanding the emission mechanisms in low-luminosity AGNs (LLAGN). Despite its proximity M81 has been subject of remarkably few in (dedicated) radio studies.
The aim of this study is to understand different properties of M81 via observations using Effelsberg Radio Telescope as well as with VLBI observations carrie
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Presented by Prathamesh Santosh INGALE
Session:
Poster Session
Current VLBI observations allow us to study collimation in relativistic AGN jets. Among AGNs, radio galaxies provide the unique opportunity to test for jet asymmetry due to their large viewing angle. To better understand the complex interplay between the dynamics of the jet and its environment, we perform numerical simulations of a double sided jet, incorporating realistic ambient profiles as well
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Presented by Mrs. Ainara SAIZ PÉREZ
Session:
Poster Session
The formation of relativistic jets from active galactic nuclei remains a subject of intense debate. Despite significant advances in understanding the underlying mechanisms, numerous questions remain. To address them, high-angular-resolution observations performed with the very long baseline interferometry (VLBI) technique are needed.
In this context, we present preliminary results on 4C +01.28 (B
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Presented by Luca RICCI
Session:
Poster Session
Understanding the feedback processes occurring in quasars and the nature of their faint radio emission is needed to reconcile known theories of galaxy formation and AGN evolution. In particular, it is not clear whether the faint radio emission from optically bright quasars is associated with weak jets, ongoing star-formation or another emission process occurring close to the black hole. To shed li
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Presented by Ms. Jayde BHANA
Session:
Poster Session
Currently viable dark matter (DM) models, such as the standard cold dark matter (CDM) model and alternative models developed to address its shortcomings - including warm DM, fuzzy DM, and self-interacting DM - differ in their predictions for DM halos at critical sub-galactic scales. If sufficiently dense, these sub-galactic DM halos could form a population of supermassive compact objects (SMCOs).
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Presented by Dr. Felix POETZL
Session:
Poster Session
The technique of frequency phase transfer (FPT), pioneered at the Korean VLBI Network, is now gaining strong momentum with a number of telescopes and VLBI arrays considering it as a backbone of future operations. These include, most notably, the Global Millimeter VLBI Array (GMVA) and the upgrade of the Event Horizon Telescope. Implementation of FPT at these instruments holds a promise of increasi
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Presented by Andrei LOBANOV
Session:
Poster Session
Pulsars are routinely observed to vary in brightness on timescales of a few minutes due to variations in electron density in the interstellar medium (ISM) on angular scales of several microarcseconds--a process known as scintillation. The only way to unambiguously measure the geometric properties of the ISM structures causing scintillation is with VLBI. However, few VLBI scintillation studies ha
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Presented by Ms. Ashley STOCK
Session:
Poster Session
MOJAVE (Monitoring Of Jets in Active galactic nuclei with VLBA Experiments) is a long-term program to monitor radio brightness and polarization variations in jets associated with active galaxies in the northern sky. It started in 1994 as the 2 cm VLBA survey, introduced polarization measurements in 2002, and is currently approved to continue until 2027.
We monitor more than 60 jets to learn how r
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Presented by Yuri KOVALEV
Session:
Poster Session
TANAMI is the only large and long-term VLBI monitoring program focused on the Southern sky aiming at VLBI monitoring of active galactic nuclei (AGN) at X and K band since 2007, and at S band since 2020. The program concentrates on AGN with very high-energy gamma-ray emission and in recent years the source sample has been extended to accommodate the emerging field of neutrino astronomy as well. Rec
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Presented by Mr. Florian RÖSCH
Session:
Poster Session
We introduce high-cadence monitoring of the M87 jet using EATING VLBI, a joint facility between the East Asia VLBI Network (EAVN) and three Italian telescopes. Currently, EATING VLBI is the only array focusing on regular monitoring of the sub-mas-scale structure of the M87 jet. Here, we present the first images from this program, successfully detecting jet emissions up to $\sim$10 mas from the cor
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Presented by Dr. Hyunwook RO
Session:
Poster Session
Global VLBI observations with baseline lengths of ~10,000km allow detailed imaging at
sub-milliarcsecond resolution at the expense of reduced observation cadence. Given the typical variability of blazars, investigation of flaring AGNs benefits from high cadence and long-term monitoring of targets of interest. Observations with a VLBI array consisting of a smaller number of antennas allow the high
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Presented by Mr. Whee Yeon CHEONG
Session:
Poster Session
Active galactic nuclei (AGN) are the most extreme sources of power in the Universe, outshining their entire host galaxies. The Event Horizon Telescope collaboration has successfully imaged supermassive black holes in M87 and SgrA* at event horizon scales, confirming theoretical predictions from general relativity. However, to determine the physical properties of these black holes, precise informa
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Presented by Prof. J. Anton ZENSUS
Session:
Poster Session
Quasi-periodic eruptions are repeating burst of X-ray emission, that occur roughly periodically on time intervals of a few hours. Only 6 QPE source were so far detected. While the underlying mechanism for the observed X-ray emission is not fully understood, it is generally believed to be caused be the interaction between a star or stellar remnant with the accretion disk of a super massive black ho
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Presented by Sebastiano Daniel VON FELLENBERG
Session:
Poster Session
Single baseline interferometre at VIRAC uses SFXC correlator. This work automated using The Automatic Correlation System (ACor) system. This system is web-based platform which one of the tasks is to automate the correlation and data processing.
The ACor system allows two types of observations to be processed: 1) Data processing with single scan correlation - to experiment with correlation param
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Presented by Mr. Jānis ŠTEINBERGS
Session:
Poster Session
We observed four confirmed dual AGNs in Stripe 82 region using VLBA at 5 GHz in multiple-phase-center mode, aiming to study their milliarcsec-scale radio emission properties. In the eight radio components of targets, we detected two pc-scale radio cores labelled J0051+0020B and J2300-0005A. The radio emission of the other six components was resolved out in the high-resolution images. The two VLBA-
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Presented by Mr. Wancheng XU
Session:
Poster Session
VLBI technique provides a means to investigate the nature of radio-emitting binary stars on mas or sub-mas scale. In astrometry, high-precision parallax, proper motion, and position measurements could be achieved through VLBI observations, assisting in the revision of our knowledge of the physical parameters of radio-emitting binary stars. Moreover, the binaries being both radio loud and optically
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Presented by Dr. Pengfei JIANG
Session:
Poster Session
I will present a new project aiming to increase the number of sources with Very Long Baseline Interferometry (VLBI) astrometry available for comparison with the Gaia results. Using the Very Long Baseline Array, we have observed 31 stars with recently reported radio emission, located <100 pc from the Sun, and all are in the Gaia DR3 catalog. Our first observations yielded 10 detections (a 30% detec
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Presented by Sergio Abraham DZIB QUIJANO
Session:
Poster Session
The extragalactic radio sources that make up the International Celestial Reference Frame (ICRF) can exhibit extended and time-variable brightness distributions (or structures) on VLBI scales, setting limits on the accuracy of the astrometric source positions determined from the VLBI measurements. For this reason, the International VLBI Service for Geodesy and Astrometry (IVS) has organized regular
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Presented by Dr. Patrick CHARLOT
Session:
Poster Session
Compact symmetric objects (CSOs) are intrinsically compact extragalactic radio sources and are thought to represent the progenitors of classical radio galaxies.
Several evolutionary models of the radio emission have been developed so far, but they mainly focus on the evolution of high-power jets. Low-power jets are more prone to instabilities than their high-power counterparts, and jet-medium int
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Presented by Dr. Filippo D'AMMANDO