A5014285382- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Neutrino Physics Research
- Astrophysical Phenomena and Observations
- Galaxies: Formation, Evolution, Phenomena
- Gamma-ray bursts and supernovae
- Dark Matter and Cosmic Phenomena
- Streptococcal Infections and Treatments
- Stellar, planetary, and galactic studies
- Pulsars and Gravitational Waves Research
- Solar and Space Plasma Dynamics
- Particle Accelerators and Free-Electron Lasers
- Astronomical Observations and Instrumentation
- Veterinary Equine Medical Research
- Astronomy and Astrophysical Research
Max Planck Institute for Radio Astronomy
2021-2024
University of Würzburg
2023-2024
Commonwealth Scientific and Industrial Research Organisation
2023
Astronomy and Space
2023
Instituto de Física Teórica
2023
University of Bologna
2023
Fischer (Germany)
2023
Eötvös Loránd University
2019
Aims. We introduce the TELAMON program which is using Effelsberg 100-m telescope to monitor radio spectra of active galactic nuclei (AGN) under scrutiny in astroparticle physics, specifically TeV blazars and candidate neutrino-associated AGN. Here, we present characterize our main sample TeV-detected blazars. Methods. analyzed data from first ∼2.5 yr observations between August 2020 February 2023 range 14 GHz 45 GHz. During this pilot phase, observed all 59 Northern Hemisphere (i.e., Dec...
Context. High-redshift blazars provide valuable input to studies of the evolution active galactic nuclei (AGN) jets and constraints on cosmological models. Detections at high energies (0.1 < E 100 GeV) these distant sources are rare, but when they exhibit bright gamma-ray flares, we able study them. However, contemporaneous multi-wavelength observations high-redshift objects ( z > 4) during their different periods activity have not been carried out so far. An excellent opportunity for...
Abstract Blazars can be detected from very large distances due to their high luminosity. However, the detection of γ -ray emission blazars beyond z = 3 has only been confirmed for a small number sources. Such observations probe growth supermassive black holes close peak star formation in history galaxy evolution. As result continuous monitoring sample 80 > with Fermi Large Area Telescope (Fermi-LAT), we present first flare 4.31 blazar TXS 1508+572. This source showed activity 2022...
Aims. The dynamics of relativistic jets in inner parsec regions are deeply affected by the nature magnetic fields. level magnetization plasma as well geometry these fields on compact scales have not yet been fully constrained. Methods. In this paper, we employ multi-frequency and multi-epoch very long baseline interferometry observations nearby radio galaxy NGC 315. We aim to derive insights into field properties sub-parsec examining observational signatures such spectral index, synchrotron...
Context. PSO J334.2028+1.4075 (PSO J334) is a luminous quasar located at redshift z = 2.06. The source gained attention when periodic flux density variations were discovered in its optical light curve. These initially interpreted as the variability due to orbital motion of supermassive black hole binary (SMBHB) residing single circumbinary accretion disk. separation was determined be 0.006 pc with an in-spiral time 7 yr rest frame J334. findings suggested could gravitational wave emitting...
Context. With the emergence of very high energy astronomy (VHE; E > 100 GeV), new open questions were presented to astronomers studying multi-wavelength emission from blazars. Answers these questions, such as Doppler crisis, and finding location high-energy activity have eluded us thus far. Recently, quasi-simultaneous monitoring programs shown considerable success in investigating blazar activity. Aims. Such observations across electromagnetic spectrum became possible thanks launch Fermi...
Aims. We introduce the TELAMON program which is using Effelsberg 100-m telescope to monitor radio spectra of active galactic nuclei (AGN) under scrutiny in astroparticle physics, specifically TeV blazars and candidate neutrino-associated AGN. Here, we present characterize our main sample TeV-detected blazars. Methods. analyze data from first ~2.5 years observations between August 2020 February 2023 range 14 GHz 45 GHz. During this pilot phase, have observed all 59 Northern Hemisphere (i.e.,...
The prominent radio quasar PKS 2215+020 (J2217+0220) was once labelled as a new laboratory for core–jet physics at redshift z=3.572 because of its exceptionally extended jet structure traceable with very long baseline interferometric (VLBI) observations up to ∼600 pc projected distance from the compact core and hint an arcsec-scale X-ray jet. While presence could not be confirmed later, this active galactic nucleus is still unique high VLBI Here, we analyse archival multi-epoch imaging data...
Radio galaxies harbouring jetted active galactic nuclei are a frequent target of very long baseline interferometry (VLBI) because they play an essential role in our exploration how jets form and propagate. Hence, only few have not yet been detected with VLBI; Fornax A was one the most famous examples. Here we present first detection compact core region VLBI. At 8.4 GHz faint is consistent unresolved point source. We constrained its flux density to be S 0 = 47.5 − 62.3 mJy diameter D min ≤ 70...
Blazars can be detected from very large distances due to their high luminosity. However, the detection of $\gamma$-ray emission blazars beyond $z=3$ has only been confirmed for a small number sources. Such observations probe growth supermassive black holes close peak star formation in history galaxy evolution. As result continuous monitoring sample 80 $z>3$ with Fermi-LAT, we present first flare $z=4.31$ blazar TXS 1508+572. This source showed activity February August 2022, reaching...
The dynamic of relativistic jets in the inner parsec regions is deeply affected by nature magnetic fields. level magnetization plasma, as well geometry these fields on compact scales, have not yet been fully constrained. In this paper we employ multi-frequency and multi-epoch very long baseline interferometry observations nearby radio galaxy NGC 315. We aim to derive insights into field properties sub-parsec scales examining observational signatures such spectral index, synchrotron turnover...
In recent years, evidence has accumulated that some high-energy cosmic neutrinos can be associated with blazars. The strongest for an individual association was found in the case of blazar TXS 0506+056 2017. July 2019, another track-like neutrino event (IC190730A) spatially coincident well-known bright flat-spectrum radio quasar PKS 1502+106. 1502+106 not to a particularly elevated gamma-ray state, but exhibited remarkably outburst at time detection, similar 0506+056. We have performed...
In recent years, evidence has accumulated that some high-energy cosmic neutrinos can be associated with blazars. The strongest for an individual association was found in the case of blazar TXS 0506+056 2017. July 2019, another track-like neutrino event (IC190730A) spatially coincident well-known bright flat-spectrum radio quasar PKS 1502+106. 1502+106 not to a particularly elevated gamma-ray state, but exhibited remarkably outburst at time detection, similar 0506+056. We have performed...
Apparently periodic optical variations of the luminous high-redshift (z=2.06) quasar PSO J334.2028+1.4075 led Liu et al. (2015) to interpret variability as orbital period a binary supermassive black hole (SMBH) residing in single circumbinary accretion disk. The proposed separation was around 0.006 pc, and possible inspiral time about 7 yr rest frame quasar. Such objects would be high interest difficult-to-find end products SMBH evolution, potential sources low-frequency gravitational waves....
Apparently periodic optical variations of the luminous high-redshift (z=2.06) quasar PSO J334.2028+1.4075 led Liu et al. (2015) to interpret variability as orbital period a binary supermassive black hole (SMBH) residing in single circumbinary accretion disk. The proposed separation was around 0.006 pc, and possible inspiral time about 7 yr rest frame quasar. Such objects would be high interest difficult-to-find end products SMBH evolution, potential sources low-frequency gravitational waves....
Abstract In recent years, evidence has started piling up that some high-energy cosmic neutrinos can be associated with blazars in flaring states. On 2022 February 26, a new blazar-neutrino coincidence was reported: the track-like neutrino event IC220225A detected by IceCube is spatially coincident flat-spectrum radio quasar PKS 0215+015. Like previous associations, this source found to high optical and γ -ray state. Moreover, showed bright outburst, which substantially increases probability...
High angular resolution observations with the very long baseline interferometry (VLBI) provide crucial tests for association of neutrinos blazars. The VLBI follow-up have led to unveiling VLBI-scales properties potentially linked neutrino production in jet blazar TXS 0506+056, first source associated a event. In order collect new pieces evidence on connection between radio blazars and production, we performed investigation gamma-ray observed spatial coincidence four events, detected by...
PSO J334.2028+1.4075 (PSO J334) is a luminous quasar located at redshift z=2.06. The source gained attention when periodic flux density variations were discovered in its optical light curve. These initially interpreted as the variability due to orbital motion of supermassive black hole binary (SMBHB) residing single circumbinary accretion disk. However, subsequent multiwavelength observations provided evidence against hypothesis no periodicity was found on extended time baselines. On other...
We present recent results of the TELAMON program, which is using Effelsberg 100-m telescope to monitor radio spectra active galactic nuclei (AGN) under scrutiny in astroparticle physics, namely TeV blazars and neutrino-associated AGN. Our sample includes all known northern TeV-emitting as well positionally coincident with IceCube neutrino alerts. Polarization can give additional insight into source properties, polarized emission often found vary on different timescales amplitudes than total...
The origin of high-energy cosmic neutrinos detected by the IceCube observatory is a hotly debated topic in astroparticle physics. There growing evidence that some these can be associated with active galactic nuclei (AGN) and especially blazars. Several recent studies have revealed statistical correlation between radio-bright AGN samples neutrino event catalogs. In addition, number individual been found to coincide radio-flaring These observational results strongly call for high-quality, high...
We present recent results of the TELAMON program, which is using Effelsberg 100-m telescope to monitor radio spectra active galactic nuclei (AGN) under scrutiny in astroparticle physics, namely TeV blazars and neutrino-associated AGN. Our sample includes all known Northern TeV-emitting as well positionally coincident with IceCube neutrino alerts. Polarization can give additional insight into source properties, polarized emission often found vary on different timescales amplitudes than total...
The origin of high-energy cosmic neutrinos detected by the IceCube observatory is a hotly debated topic in astroparticle physics. There growing evidence that some these can be associated with active galactic nuclei (AGN) and especially blazars. Several recent studies have revealed statistical correlation between radio-bright AGN samples neutrino event catalogs. In addition, number individual been found to coincide radio-flaring These observational results strongly call for high-quality, high...
With the emergence of very high energy astronomy (VHE; E>100 GeV), new open questions were presented to astronomers studying multi-wavelength emission from blazars. Answers these questions, such as Doppler crisis, and finding location high-energy activity have eluded us thus far. Recently, quasi-simultaneous monitoring programs shown considerable success in investigating blazar activity. After launch Fermi Gamma-ray Space Telescope 2008, observations across electromagnetic spectrum became...