activity
20112021
most citedThe Milky Way's Supermassive Black Hole: How good a case is it? A Challenge for Astrophysics & Philosophy of Science

129 citations · 884 across the 36 of their papers we have counts for

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Showing astro-ph.GAShow all

22 papers · 1 filter

astro-ph.GA2021★ 7 cited

Gas and stellar dynamics in Stephan's Quintet: Mapping the kinematics in a closely interacting compact galaxy group

M. Yttergren, P. Misquitta, Á. Sánchez-Monge +4

Stephan's Quintet (SQ) is a nearby compact galaxy group and a perfect laboratory for studying the process of galaxy evolution through galaxy harassment and interaction. By analysin…

astro-ph.GA2020★ 49 cited

Kinematic Structure of the Galactic Center S-cluster

Basel Ali, Daria Paul, Andreas Eckart +7

We present a detailed analysis of the kinematics of 112 stars that mostly comprise the high velocity S-cluster and orbit the super massive black hole SgrA* at the center of the Mil…

astro-ph.GA2020★ 1 cited

Interactions among intermediate redshift galaxies. The case of SDSSJ134420.86+663717.8

Persis Misquitta, Micah Bowles, Andreas Eckart +4

We present the properties of the central supermassive black holes and the host galaxies of the interacting object SDSSJ134420.86+663717.8. We obtained optical long slit spectroscop…

astro-ph.GA2019★ 30 cited

Monitoring dusty sources in the vicinity of Sgr A*

F. Peißker, S. E. Hosseini, M. Zajacek +5

We trace several dusty infrared sources on their orbit around the supermassive black hole (SMBH) SgrA* in the center of our galaxy. We give an overview of known and unknown sources…

astro-ph.GA2019★ 31 cited

Radio spectral index distribution of SDSS-FIRST sources across optical diagnostic diagrams

Michal Zajaček, Gerold Busch, Mónica Valencia-S. +7

A detailed understanding of how the activity of a galactic nucleus regulates the growth of its host is still missing. To understand the activity and the types of accretion of super…

astro-ph.GA2019

Bow shock sources close to the Galactic centre

Michal Zajacek, Andreas Eckart, Seyedeh Elaheh Hosseini

We provide an up-to-date summary of the current observational and theoretical studies of stellar bow-shock sources close to the Galactic centre. The symmetry axis of a bow shock pr…

astro-ph.GA2019★ 28 cited

Near-infrared observations of star formation and gas flows in the NUGA galaxy NGC 1365

Nastaran Fazeli, Gerold Busch, Monica Valencia-S. +4

In the framework of understanding the gas and stellar kinematics and their relations to AGNs and galaxy evolution scenarios, we present spatially resolved distributions and kinemat…

astro-ph.GA2017★ 36 cited

Bright X-ray flares from Sgr A*

G. D. Karssen, M. Bursa, A. Eckart +4

We address a question whether the observed light curves of X-ray flares originating deep in galactic cores can give us independent constraints on the mass of the central supermassi…

astro-ph.GA2017

Nuclear Activity and the Conditions of Star-formation at the Galactic Center

A. Eckart, M. Valencia-S., B. Shahzamanian +15

The Galactic Center is the closest galactic nucleus that can be studied with unprecedented angular resolution and sensitivity. We summarize recent basic observational results on Sa…

astro-ph.GA2017★ 9 cited

A low-luminosity type-1 QSO sample: IV. Molecular gas contents and conditions of star formation in three nearby Seyfert galaxies

Lydia Moser, Melanie Krips, Gerold Busch +8

We present a pilot study of ~ 3" resolution observations of low CO transitions with the Submillimeter Array in three nearby Seyfert galaxies, which are part of the low-luminosity q…

astro-ph.GA2016★ 28 cited

Star formation and gas flows in the centre of the NUGA galaxy NGC 1808 observed with SINFONI

Gerold Busch, Andreas Eckart, Mónica Valencia-S. +4

NGC 1808 is a nearby barred spiral galaxy which hosts young stellar clusters in a patchy circumnuclear ring with a radius of . In order to study the gaseous…

astro-ph.GA2016★ 26 cited

Polarized near-infrared light of the Dusty S-cluster Object (DSO/G2) at the Galactic Center

B. Shahzamanian, A. Eckart, M. Zajacek +6

We investigate an infrared-excess source called G2 or Dusty S-cluster Object (DSO) moving on a highly eccentric orbit around the Galaxy's central black hole, Sgr A*. We use, for th…

astro-ph.GA2015★ 12 cited

A low-luminosity type-1 QSO sample. V. Overluminous host spheroids and their excitation mechanisms

Gerold Busch, Nastaran Fazeli, Andreas Eckart +6

We present near-infrared (NIR) -band longslit spectra of eleven galaxies which are obtained with SOFI at the NTT (ESO). The galaxies are chosen from the low-luminosity type-1…

astro-ph.GA2015★ 10 cited

Line and Continuum Variability in Active Galaxies

Y. E. Rashed, A. Eckart, M. Valencia-S. +5

We compared optical spectroscopic and photometric data for 18 AGN galaxies over 2 to 3 epochs, with time intervals of typically 5 to 10 years. We used the Multi-Object Double Spect…

astro-ph.GA2015★ 2 cited

The Galactic Center Black Hole Laboratory

A. Eckart, S. Britzen, M. Valencia-S. +8

The super-massive 4 million solar mass black hole Sagittarius~A* (SgrA*) shows flare emission from the millimeter to the X-ray domain. A detailed analysis of the infrared light cur…

astro-ph.GA2014★ 13 cited

A low-luminosity type-1 QSO sample: II. Tracing circumnuclear star formation in HE 1029-1831 with SINFONI

Gerold Busch, Semir Smajić, Julia Scharwächter +6

Circumnuclear star formation and AGN feedback is believed to play a critical role in the context of galaxy evolution. The low-luminosity QSO (LLQSO) sample that contains 99 of the…

astro-ph.GA2014★ 53 cited

Monitoring the Dusty S-Cluster Object (DSO/G2) on its Orbit towards the Galactic Center Black Hole

M. Valencia-S., A. Eckart, M. Zajacek +23

We analyse and report in detail new near-infrared (1.45 - 2.45 microns) observations of the Dusty S-cluster Object (DSO/G2) during its approach to the black hole at the center of t…

astro-ph.GA2014★ 18 cited

ALMA backed NIR high resolution integral field spectroscopy of the NUGA galaxy NGC 1433

Semir Smajic, Lydia Moser, Andreas Eckart +7

We present the results of near-infrared (NIR) H- and K-band European Southern Observatory SINFONI integral field spectroscopy (IFS) of the Seyfert 2 galaxy NGC 1433. We present emi…

astro-ph.GA2013★ 2 cited

The infrared K-band identification of the DSO/G2 source from VLT and Keck data

Andreas Eckart, M. Horrobin, S. Britzen +24

A fast moving infrared excess source (G2) which is widely interpreted as a core-less gas and dust cloud approaches Sagittarius A* (SgrA*) on a presumably elliptical orbit. VLT K_s-…

astro-ph.GA2013★ 3 cited

The Galactic Center as a Paradigm for Low Luminosity Nuclei? The K-band identification of the DSO/G2 source from VLT and Keck data

Andreas Eckart, S. Britzen, M. Horrobin +27

The super-massive 4 million solar mass black hole (SMBH) SgrA* shows flare emission from the millimeter to the X-ray domain. The nucleus of the Milky Way has properties (stellar cl…

astro-ph.GA2012★ 52 cited

The S-Star Cluster at the Center of the Milky Way: On the nature of diffuse NIR emission in the inner tenth of a parsec

Nadeen Sabha, Andreas Eckart, David Merritt +9

Sagittarius A*, the super-massive black hole at the center of the Milky Way, is surrounded by a small cluster of high velocity stars, known as the S-stars. We aim to constrain the…

astro-ph.GA2012★ 30 cited

The Galactic centre mini-spiral in the mm-regime

D. Kunneriath, A. Eckart, S. N. Vogel +10

The mini-spiral is a feature of the interstellar medium in the central ~2 pc of the Galactic center. It is composed of several streamers of dust and ionised and atomic gas with tem…