431 citations · 2.6k across the 47 of their papers we have counts for
29 papers · 1 filter
Ram-pressure stripped molecular gas in the Virgo spiral galaxy NGC 4522
B. Vollmer, J. Braine, C. Pappalardo +1
IRAM 30m 12CO(1-0) and 12CO(2-1) HERA observations are presented for the ram-pressure stripped Virgo spiral galaxy NGC 4522. The CO emission is detected in the galactic disk and th…
Starbursts and torus evolution in AGN
B. Vollmer, T. Beckert, R. Davies
Recent VLT SINFONI observations of the close environments (~30pc) of nearby AGNs have shown that thick gas tori and starbursts with ages between 10 and 150Myr are frequently found.…
Quasi-simultaneous multi-frequency observations of inverted-spectrum GPS candidate sources
B. Vollmer, T. P. Krichbaum, E. Angelakis +1
Gigahertz-Peaked Spectrum (GPS) sources are probably the precursors of local radio galaxies.Existing GPS source samples are small (<200). It is necessary to extend the availabe sam…
Pre-peak ram pressure stripping in the Virgo cluster spiral galaxy NGC 4501
B. Vollmer, M. Soida, A. Chung +5
VIVA HI observations of the Virgo spiral galaxy NGC 4501 are presented. The HI disk is sharply truncated to the southwest, well within the stellar disk. A region of low surface-den…
Virgo Galaxies with Long One-Sided HI Tails
Aeree Chung, J. H. van Gorkom, Jeffrey D. P. Kenney +1
In a new HI imaging survey of Virgo galaxies (VIVA: VLA Imaging of Virgo galaxies in Atomic gas), we find 7 spiral galaxies with long HI tails. The morphology varies but all the ta…
The characteristic polarized radio continuum distribution of cluster spiral galaxies
B. Vollmer, M. Soida, R. Beck +5
Deep observations of 6cm polarized radio continuum emission of 8 Virgo spiral galaxies are presented. All galaxies show strongly asymmetric distributions of polarized intensity wit…
Deep HI observations of the surroundings of ram pressure stripped Virgo spiral galaxies - Where is the stripped gas?
B. Vollmer, W. Huchtmeier
Deep Effelsberg 100-m HI observations of 5 HI deficient Virgo spiral galaxies are presented. No new extended HI tail is found in these galaxies. The already known HI tail north of…
Observations of Stripped Edge-on Virgo Cluster Galaxies
Hugh H. Crowl, Jeffrey D. P. Kenney, J. H. van Gorkom +1
We present observations of highly inclined, HI deficient, Virgo cluster spiral galaxies. Our high-resolution VLA HI observations of edge-on galaxies allow us to distinguish extrapl…
New CO observations and simulations of the NGC 4438/NGC 4435 system
B. Vollmer, J Braine, F. Combes +1
NGC 4438 is a highly perturbed spiral with a stellar tidal tail and extraplanar molecular gas, now very HI deficient, crossing the center of the Virgo cluster at high speed. Variou…
Dense Cloud Ablation and Ram Pressure Stripping of the Virgo Spiral NGC 4402
Hugh H. Crowl, Jeffrey D. P. Kenney, J. H. van Gorkom +1
We present optical, HI and radio continuum observations of the highly inclined Virgo Cluster Sc galaxy NGC 4402, which show evidence for ram-pressure stripping and dense cloud abla…
A method for determining radio continuum spectra, and its application to large surveys
B. Vollmer, E. Davoust, P. Dubois +3
A new tool to extract cross-identifications and radio continuum spectra from radio catalogues contained in the VIZIER database of the CDS is presented. The code can handle radio su…
Torus models for obscuration in type 2 AGN
Thomas Beckert, Wolfgang J. Duschl, Bernd Vollmer
We discuss a clumpy model of obscuring dusty tori around AGN. Cloud-cloud collisions lead to an effective viscosity and a geometrically thick accretion disk, which has the required…
A Virgo high-resolution Halpha kinematical survey
L. Chemin, C. Balkowski, V. Cayatte +9
We have completed a survey of 30 Virgo cluster galaxies in the Halpha emission-line using Fabry-Perot interferometry. The goal of the survey is to obtain a high angular resolution…
Spiral Galaxy - ICM Interactions in the Virgo Cluster
Jeffrey D. P. Kenney, Hugh Crowl, Jacqueline van Gorkom +1
We discuss HI and optical evidence for ongoing ICM-ISM interactions in 6 HI-deficient Virgo cluster spiral galaxies. One of the clearest cases is the highly inclined Virgo galaxy N…
Radio continuum observations of the Virgo cluster spiral NGC 4522 The signature of ram pressure
B. Vollmer, R. Beck, J. D. P. Kenney +1
Radio continuum observations at 20 and 6 cm of the highly inclined Virgo spiral galaxy NGC 4522 are presented. Both, 20 and 6 cm total emission distributions are asymmetric with an…
NGC 4569: recent evidence for a past ram pressure stripping event
B. Vollmer, C. Balkowski, V. Cayatte +2
Deep 21-cm HI line observations of the Virgo cluster spiral galaxy NGC 4569 have been obtained with the VLA in its D configuration and with the Effelsberg 100-m telescope. A low su…
Radio continuum spectra of galaxies in the Virgo cluster region
B. Vollmer, M. Thierbach, R. Wielebinski
New radio continuum observations of galaxies in the Virgo cluster region at 4.85, 8.6, and 10.55 GHz are presented. These observations are combined with existing measurements at 1.…
From the Circumnuclear Disk in the Galactic Center to thick, obscuring tori of AGNs
B. Vollmer, T. Beckert, W. J. Duschl
We compare three different models of clumpy gas disk and show that the Circumnuclear Disk (CND) in the Galactic Center and a putative, geometrically thick, obscuring torus are best…
Environmental Effects on the Kinematics of Virgo Cluster Galaxies
L. Chemin, V. Cayatte, C. Balkowski +9
We present results from an ongoing survey dedicated to the ionized gas kinematics of Virgo cluster spiral galaxies using Fabry-Perot interferometry. Our goal is to study the enviro…
The line-of-sight distribution of the gas in the inner 60 pc of the Galaxy
B. Vollmer, R. Zylka, W. J. Duschl
2MASS K_S band data of the inner 60 pc of the Galaxy are used to reconstruct the line-of-sight distances of the giant molecular clouds located in this region. Using the 2MASS H ban…
Gas physics and dynamics in the central 50 pc of the Galaxy
B. Vollmer, W. J. Duschl, R. Zylka
We present models the gas physics and dynamics of the inner 50 pc of the Galaxy. In a first step the gas properties of an isolated clumpy circumnuclear disk were analytically inves…
NGC 4654: gravitational interaction or ram pressure stripping?
B. Vollmer
The Virgo cluster spiral galaxy NGC 4654 is supposed to be a good candidate for ongoing ram pressure stripping based on its very asymmetric HI distribution. However, this galaxy al…
The dynamics of the Circumnuclear Disk and its environment in the Galactic centre
B. Vollmer, W. J. Duschl
We address the question of the dynamics in the inner 50 pc of the Galactic Centre. In a first step we investigate the cloud-cloud collision rate in the Circumnuclear Disk (CND) wit…
Ram pressure stripping and galaxy orbits: The case of the Virgo cluster
B. Vollmer, V. Cayatte, C. Balkowski +1
We investigate the role of ram pressure stripping in the Virgo cluster using N-body simulations. Radial orbits within the Virgo cluster's gravitational potential are modeled and an…