L. Burtscher
A5071163045- Galaxies: Formation, Evolution, Phenomena
- Astrophysical Phenomena and Observations
- Astrophysics and Star Formation Studies
- Astronomy and Astrophysical Research
- Stellar, planetary, and galactic studies
- Adaptive optics and wavefront sensing
- Astronomical Observations and Instrumentation
- Gamma-ray bursts and supernovae
- Calibration and Measurement Techniques
- Conferences and Exhibitions Management
- Spectroscopy and Laser Applications
- Astrophysics and Cosmic Phenomena
- Radio Astronomy Observations and Technology
- Astro and Planetary Science
- Climate Change and Health Impacts
- History and Developments in Astronomy
- Advanced Measurement and Metrology Techniques
- Advanced optical system design
- Atmospheric and Environmental Gas Dynamics
- Delphi Technique in Research
- Pulsars and Gravitational Waves Research
- Scientific Measurement and Uncertainty Evaluation
- Ionosphere and magnetosphere dynamics
- Aviation Industry Analysis and Trends
- Geophysics and Gravity Measurements
Leiden University
2017-2024
Leiden Observatory
2017-2024
Altrecht GGZ
2021
Netherlands Institute for Radio Astronomy
2020
Max Planck Institute for Extraterrestrial Physics
2012-2018
Novay
2018
Max Planck Society
2009-2015
Max Planck Institute for Astronomy
2009-2013
GRAVITY is a new instrument to coherently combine the light of European Southern Observatory Very Large Telescope Interferometer form telescope with an equivalent 130 m diameter angular resolution and collecting area 200 m$^2$. The comprises fiber fed integrated optics beam combination, high spectroscopy, built-in analysis control, near-infrared wavefront sensing, phase-tracking, dual operation laser metrology [...]. This article gives overview reports on performance first astronomical...
The AGN-heated dust distribution (the "torus") is increasingly recognized not only as the absorber required in unifying models, but a tracer for reservoir that feeds nuclear Super-Massive Black Hole. Yet, even its most basic structural properties (such extent, geometry and elongation) are unknown all few archetypal objects. Since AGNs unresolved mid-infrared, we utilize MID-infrared interferometric Instrument (MIDI) at Very Large Telescope Interferometer (VLTI) sensitive to structures small...
Dust around active galactic nuclei (AGNs) is distributed over a wide range of spatial scales and can be observed in the infrared (IR). It generally assumed that distribution on parsec forms geometrically optically thick entity equatorial plane accretion disk broad-line region—dubbed "dust torus"—that emits bulk subarcsecond-scale IR emission gives rise to orientation-dependent obscuration. However, recent interferometry studies with unprecedented position angle (P.A.) baseline coverage these...
Context. With infrared interferometry it is possible to resolve the nuclear dust distributions that are commonly associated with dusty torus in active galactic nuclei (AGN). The Circinus galaxy hosts closest Seyfert 2 nucleus and previous interferometric observations have shown its emission particularly well resolved.
Context. Detailed high resolution studies of AGN with mid-infrared (MIR) interferometry have revealed parsec-sized dust emission elongated in the polar direction four sources. Aims. Using a larger, coherently analyzed sample observed MIR interferometry, we aim to identify statistical More specifically wish determine if there is indeed preferred elongation and whether this consistent torus-like structure or emission. Methods. We investigate significance detection an shape by fitting Gaussian...
We analyse the 2-dimensional distribution and kinematics of stars as well molecular ionised gas in central few hundred parsecs 5 active matched inactive galaxies. The equivalent widths Br-gamma line indicate there is no on-going star formation their nuclei, although recent (terminated) starbursts are possible stellar velocity fields show signs non-circular motions, while 1-0S(1) H_2 exhibit significant deviations from simple circular rotation. In galaxies reveal inflow outflow superimposed...
We report on the determination of electron densities, and their impact outflow masses rates, measured in central few hundred parsecs 11 local luminous active galaxies. show that peak integrated line emission AGN is significantly offset from systemic velocity as traced by stellar absorption features, indicating profiles are dominated outflow. In contrast, matched inactive galaxies characterised a weaker wing. present three independent estimates density these AGN, discussing merits different...
We present the first results of Galaxy Activity, Torus and Outflow Survey (GATOS), a project aimed at understanding properties dusty molecular tori their connection to host galaxy in nearby Seyfert galaxies. Our expands range AGN luminosities Eddington ratios covered by previous surveys Seyferts conducted ALMA allows us study gas feeding feedback cycle combined sample 19 Seyferts. used obtain new images emission dust using CO(3-2) HCO+(4-3) lines as well underlying continuum 870 microns with...
Abstract We present the active galactic nucleus (AGN) catalog and optical spectroscopy for second data release of Swift BAT AGN Spectroscopic Survey (BASS DR2). With this DR2 we provide 1449 spectra, which 1182 are released first time, 858 hard-X-ray-selected AGNs in 70-month sample. The majority spectra (801/1449, 55%) newly obtained from Very Large Telescope (VLT)/X-shooter or Palomar/Doublespec. Many have both higher resolution ( R > 2500, N ∼ 450) and/or very wide wavelength coverage...
Context:Optical interferometry is at a key development stage. ESO's VLTI has established stable, robust infrastructure for long-baseline general astronomical observers. The present second-generation instruments offer wide wavelength coverage and improved performance. Their sensitivity measurement accuracy lead to data images of high reliability. Aims:We have developed MATISSE, the Multi AperTure mid-Infrared SpectroScopic Experiment, access resolution imaging in spectral domain explore...
Abstract We present measurements of broad emission lines and virial estimates supermassive black hole masses ( M BH ) for a large sample ultrahard X-ray-selected active galactic nuclei (AGNs) as part the second data release BAT AGN Spectroscopic Survey (BASS/DR2). Our catalog includes total 689 AGNs, determined from H α , β Mg ii λ 2798, and/or C iv 1549 lines. The core 512 AGNs drawn 70 month Swift/BAT all-sky catalog. also provide 177 additional that are deeper survey data. study links...
<i>Aims. <i/>The emission of warm dust dominates the mid-infrared spectra active galactic nuclei (AGN). Only interferometric observations provide necessary angular resolution to resolve nuclear and study its distribution properties. The investigation in AGN cores is hence one main science goals for MID-infrared Interferometric instrument MIDI at VLTI. As first step, feasibility was verified most promising sources detailed studies were identified.<i>Methods. <i/>This carried out a "snapshot...
We describe a complete volume limited sample of nearby active galaxies selected by their 14–195 keV luminosity, and outline its rationale for studying the mechanisms regulating gas inflow outflow. also complementary inactive galaxies, to match host galaxy properties. The appears have no bias in terms galactic nucleus (AGN) type, only difference being neutral absorbing column, which is two orders magnitude greater Seyfert 2s. In luminosity range spanned sample, –43.7, optically obscured X-ray...
We combine two approaches to isolate the AGN luminosity at near-infrared wavelengths and relate near-IR pure other tracers of AGN. Using integral-field spectroscopic data an archival sample 51 local AGNs, we estimate fraction non-stellar light by comparing nuclear equivalent width stellar 2.3 micron CO absorption feature with intrinsic value for each galaxy. compare this that derived from a spectral decomposition integrated in central arc second find them be consistent other. our estimates...
ABSTRACT We report on our combined analysis of HST, VLT/MUSE, VLT/SINFONI, and ALMA observations the local Seyfert 2 galaxy, NGC 5728 to investigate in detail feeding feedback active galactic nucleus (AGN). The data sets simultaneously probe morphology, excitation, kinematics stars, ionized gas, molecular gas over a large range spatial scales (10 pc 10 kpc). contains stellar bar that is driving along prominent dust lanes inner 1 kpc where settles into circumnuclear ring. ring strongly star...
Using new APEX and JCMT spectroscopy of the CO 2-1 line, we undertake a controlled study cold molecular gas in moderately luminous Active Galactic Nuclei (AGN) inactive galaxies from Luminous Local AGN with Matched Analogs (LLAMA) survey. We use spatially resolved infrared photometry LLAMA 2MASS, WISE, IRAS & Herschel, corrected for nuclear emission using multi-component spectral energy distribution (SED) fits, to examine dust-reprocessed star-formation rates (SFRs), fractions star formation...
Active galactic nuclei play a key role in the evolution of galaxies, but their inner workings and physical connection to host are poorly understood due lack angular resolution. Infrared interferometry makes it possible resolve circumnuclear dust nearby Seyfert 2 galaxy, Circinus. Previous observations have revealed complex structures polar emission interpretation was limited simple models. MATISSE image these for first time. We observed Circinus Galaxy with VLTI/MATISSE, producing 150...
ABSTRACT We present the hot molecular and warm ionized gas kinematics for 33 nearby (0.001 ≲ z 0.056) X-ray selected active galaxies using H$_2\, 2.1218\, \mu$m Br γ emission lines observed in K band with Gemini near-infrared integral field spectrograph. The observations cover inner 0.04–2 kpc of each galactic nucleus at spatial resolutions 4–250 pc a velocity resolution σinst ≈ 20 ${\rm km\, s^{-1}}$. find that 31 objects (94 per cent) kinematically disturbed region (KDR) seen gas, while...
To understand the relation between small "obscuring torus" and dusty structures at larger scales (5-10 pc) in NGC 1068, we use ESO's Mid-Infrared Interferometer (MIDI) with 1.8 m Auxiliary Telescopes to achieve necessary spatial resolution (~ 20-100 millarcsec). We chromatic phases data improve fidelity of analysis. present interferometric for 1068 obtained 2007 2012. find no evidence source variability. Many (u,v) points show non-zero indicating significant asymmetries. Gaussian model...
Context. Circumstellar disks are believed to be the birthplace of planets and expected dissipate on a timescale few Myr. The processes responsible for removal dust gas will strongly modify radial distribution circumstellar matter consequently spectral energy distribution. In particular, young planet open gap, resulting in an inner disk dominating near-IR emission outer emitting mostly far-infrared.
We use high spectral resolution (R > 8000) data covering 3800-13000\r{A} to study the physical conditions of broad line region (BLR) nine nearby Seyfert 1 galaxies. Up six HI lines are present in each spectrum. A comparison - for first time using simultaneous optical near-infrared observations photoionisation calculations with our devised simple scheme yields extinction BLR at same as determining density and photon flux, hence distance from nucleus, emitting gas. This points a typical gas...
We present the Mid-infrared stellar Diameters and Fluxes compilation Catalogue (MDFC) dedicated to long-baseline interferometry at mid-infrared wavelengths (3-13 mum). It gathers data for half a million stars, i.e. nearly all stars of Hipparcos-Tycho catalogue whose spectral type is reported in SIMBAD database. cross-match 26 databases provide basic information, binarity elements, angular diameter, magnitude flux near mid-infrared, as well flags that allow us identify potential calibrators....