Huib Jan van Langevelde

Parallaxes and proper motions of interstellar masers toward the Cygnus X star-forming complex

K. L. J. Rygl∗a, A. Brunthalerb, A. Sannab, K. M. Mentenb, M. J. Reidc, H. J. van Langevelded, f , M. Honmae, K. J. E. Torstensson f ,d, and K. Fujisawag aIstituto di Astrofisica e Planetologia Spaziali (INAF-IAPS), Via del fosso del cavaliere 100, 00133 Roma, Italy b Max-Planck-Institut für Radiostronomie (MPIfR), Auf dem Hügel 69, 53121 Bonn, Germany c Harvard Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138, USA d Joint Institute for VLBI in Europe (JIVE), Postbus 2, 7990 AA Dwingeloo, the Netherlands e Mizusawa VLBI Observatory, National Astronomical Observatory of Japan (NAOJ), 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan f Sterrewacht Leiden, Leiden University, Postbus 9513, 2300 RA Leiden, the Netherlands gFaculty of Science, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8512, Japan E-mail: kazi.rygl@inaf.it

QUANTUM-CHEMICAL CALCULATIONS REVEALING THE EFFECTS OF MAGNETIC FIELDS ON METHANOL

BOY LANKHAAR, Onsala Space Observatory, Chalmers University of Technology, Onsala, Sweden; AD VAN DER AVOIRD, Institute for Molecules and Materials (IMM), Radboud University Nijmegen, Nijmegen, Netherlands; WOUTER H.T. VLEMMINGS, Onsala Space Observatory, Chalmers University of Technology, Onsala, Sweden; GERRIT GROENENBOOM, Institute for Molecules and Materials (IMM), Radboud University Nijmegen, Nijmegen, Netherlands; HUIB JAN VAN LANGEVELDE, , Joint Institute for VLBI in Europe, Dwingeloo, Netherlands; GABRIELE SURCIS, Istituto Nazionale di Astrofisica, Osservatorio Astronomico di Cagliari, Selargius, Italy.

The first scientific experiment using Global e-VLBI observations: a multiwavelength campaign on the gamma-ray Narrow-Line Seyfert 1 PMN J0948+0022

The detection of gamma-ray emission by Fermi-LAT from the radio loud Narrow Line Seyfert 1 PMN J0948+0022 (Abdo et al. 2009, ApJ 699, 976) triggered a multi-wavelength campaign between March and July 2009. Given its high compactness (Doi et al. 2006, PASJ 58, 829), inverted spectrum, and 0deg declination, the source was an ideal target to observe at 22 GHz with a Global VLBI array extending from Europe to East Asia and Australia. In order to deliver prompt results to be analysed in combination with the other instruments participating in the campaign, the observations were carried out with real time VLBI, for the first time on a Global scale. Indeed, the main results have been published just a few months after the campaign (Abdo et al. 2009, ApJ 707, 727). Here we present additional details about the e-VLBI observations.

Maser observations - from the kinematics to the physics of evolved star winds.

M13 9PL, UK. cSwinburne University of Technology, Victoria, Australia dToruń Centre for Astronomy, Nicolaus Copernicus Universi ty, Poland e University of Kentucky, Department of Physics and Astronom y, USA f ESO, D-85748 Garching-bei-München, Germany gMPIfR, 53121 Bonn, Germany hLeiden University & JIVE, PO Box 2, NL-7990 AA Dwingeloo, NL iDepartment of Physics and Astronomy, UCL, London WC1E 6BT, U K

The compact radio counterpart of IGR J20187+4041 near the flaring source AGL 2021+4029 and 3EG J2020+4017

We present radio results from short e-EVN (European VLBI net work) observations of the counterpart to IGR J20187+4041, a hard X-ray source projected again st theγ Cygni supernova remnant (SNR). The brightest unidentified EGRET source 3EG J2020+40 17 is also located in the γ Cygni region, though its relation to IGR J20187+4041 has not been w ll established yet. The e-EVN observations were carried out following the AGILE detectio n of gamma-ray flaring activity in the region. Our observations show that the radio counterpar t to the IGR source has a compact structure on the∼10 mas scales that could be related to a compact object, but no radi flaring activity has been observed. e-VLBI ∗ is a technique which makes it possible to image the structure of radio sources at the highest angular resolution on a very s hort timescale.

Methanol masers survey using EVN

We present the results of five year campaign observing 6.7 GHz methanol masers towards the Galactic plane using European Very Long Baseline Interferometer Network (EVN). 31 out of 33 sources were imaged at milliarcsecond scale. Suprisingly, 12 of them showed an elliptical morphology which has not been detected before. We state that the recent increase of the sensitivity of EVN allowed us to detect a new type of masers. We discuss the origin of elliptically shaped methanol masers in massive star forming regions analysing their detailed structures.

EVN observations of the methanol masers in Cep A

We present EVN observations of the 6.7 GHz methanol maser in t he high mass star-forming region Cepheus A. The maser emission arises in a filamentary str ucture over∼1200 AU, straddling the waist of the thermal jet HW2. The velocity field of the metha nol masers shows an infall signature rather than a rotation signature. We present a model i n which the methanol maser emission arises in a shock interface between the infalling gas and the accretion disk/process. The model is supported by the fact that we do not see any maser emission fro m the rear side of the ring which is shielded by the ionised gas in the thermal jet. We also pres ent preliminary results of JCMT observations of thermal methanol in Cep A. The large scale mo l cular outflow provides further constrains on the geometry.

Where methanol masers spring

We are carrying out a program to observe the 6.7 GHz methanol maser emission in high-mass star-forming regions using large FOV (∼2’), astrometric, VLBI data. Here we report on the first results of the inner few arc seconds in Cepheus A East. We find a maser filament extending over ∼1.7” (1200 AU), straddling the waist of Cep A HW2. The region in which the CH3OH masers are found contains several YSO’s and it is not clear whether the CH3OH masers are associated with several different objects or rather the larger scale surrounding environment.

G23.657−0.127, what can we learn from a perfect methanol maser source?

In the course of following up compact methanol masers at 6.7 GHz which were found in the Torun blind survey (Szymczak et al. 2002), we discovered a ring structure in the source G23.657−00.127. This source provides interesting insights into whether methanol masers arise in rotating disks around massive stars, in their outflows, or behind shocks. By monitoring the 12.2 GHz masers, which fortunately follow the same structure, we hope to resolve the kinematics of the ring. Moreover, the symmetry of the source points to the existence of a central source. Early results on the nature of this source indicate the existence of a hyper–compact H II region.