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Papers by Richard Wielebinski

Research paper thumbnail of Pulse shapes of radio pulsars at 4.85 GHz

Astronomy and Astrophysics Supplement Series, 1998

Research paper thumbnail of Polarized Radio Emission of Edge-on Galaxies Observational Results and Implications

Proceedings of the International Astronomical Union

Research paper thumbnail of Galactic and Extragalactic Magnetic Fields

Reviews in Modern Astronomy, 1995

... 1988). More recently high efficiency half-wave plates were used in the JCMT telescope for sub... more ... 1988). More recently high efficiency half-wave plates were used in the JCMT telescope for sub-mm polarimetery (Murray et al 1992). ... Surveys at 1400 MHz by Bingham (1966), andSpoelstra (1971; 1984) added new information on selected areas. ...

Research paper thumbnail of Galactic and Extragalactic Magnetic Fields

Reviews in Modern Astronomy, 1995

... 1988). More recently high efficiency half-wave plates were used in the JCMT telescope for sub... more ... 1988). More recently high efficiency half-wave plates were used in the JCMT telescope for sub-mm polarimetery (Murray et al 1992). ... Surveys at 1400 MHz by Bingham (1966), andSpoelstra (1971; 1984) added new information on selected areas. ...

Research paper thumbnail of Radio continuum observations of nearby galaxies

Monthly Notices of the Royal Astronomical Society, 1987

... Although NGC 1553 is a normal SO galaxy with no bar, it has a lens with high surface brightne... more ... Although NGC 1553 is a normal SO galaxy with no bar, it has a lens with high surface brightness and a prominent nucleus ... Both CG and NGC 4945 have nuclear H20 maser emission at least an order of magnitude greater than W49, the strongest Galactic source (Gardner & ...

Research paper thumbnail of IAU Historic Radio Astronomy Working Group. Triennial Report (2003-2006)

Research paper thumbnail of The IAU Historic Radio Astronomy Working Group. 3: Progress Report (2006-2009)

Research paper thumbnail of Formation of Molecular Gas Rings in Galaxies

Proceedings of the International Astronomical Union, 1991

Research paper thumbnail of Molecular distribution and kinematics in nearby galaxies. I. NGC 253

Astron Astrophys, 1996

The central 80"x60" of the edge-on starburst galaxy NGC 253 has been mapped in the J=2-1 line of ... more The central 80"x60" of the edge-on starburst galaxy NGC 253 has been mapped in the J=2-1 line of ^12^CO with the IRAM 30m telescope (beam width: 12"). After a Lucy deconvolution, the resolution is enhanced to ~4". CO emission is strongly concentrated toward a region elongated along the major axis with a FWHP size of 34"x11" (410pcx130pc at D=2.5Mpc). Toward the center of NGC 253, the ^12^CO(2-1) line contributes between 20% and 35% to the total measured 1.3mm "continuum" in a 50GHz wide bandpass. Position-velocity maps reveal two condensations symmetrically placed with respect to the nucleus. Distinct velocity features suggest the presence of a compact molecular spiral, although a molecular bar or ring cannot be excluded. The dynamical mass in the inner 480pc is 2.610^9^Msun_. Applying a "standard" N(H_2_)/I(CO) conversion factor of 2x10^20^cm^-2^/Kkm/s, the molecular gas mass of the central condensations would be ~3x10^8^Msun_. Other tracers of molecular mass, namely optically thin C^18^O rotational lines and the mm-wave dust continuum yield gas masses of 4x10^7^...6x10^7^Msun_. The most plausible explanation of this discrepancy is that the "standard" H_2_ mass/CO luminosity ratio, which has been derived for Galactic disk clouds, cannot be applied to the bulge region of galaxies such as NGC 253. Possible reasons are discussed in terms of excitation conditions and the influence of the stellar gravitational potential. It is not the gas mass that makes NGC 253 an outstanding galaxy but its infrared luminosity and the "star forming efficiency" L_IR_/M_gas_ of 90Lsun_/Msun_.

Research paper thumbnail of Radio Studies of Galactic Objects, Galaxies and AGNs

The Sino-German Radio Astronomy Conference was held in Xi'an between July 18th and 25th 2002. Thi... more The Sino-German Radio Astronomy Conference was held in Xi'an between July 18th and 25th 2002. This conference was also a meeting of radio astronomy in China. The partner group of Max-Plack-Institut for Radioastronomie at National Astronomical Observatories of China took the responsibility for detailed organizations. The conference was focused on "Radio studies of Galactic objects, galaxies and AGNs", with 80 partici- pants plus the 6 helpers. Most radio astronomers in China together with about 30 students enjoyed the fruitful discussions with 9 German senior scientists and 6 famous experts from other countries. In addition, the his- torical sites and culture environments specifically in Xi'an also attracted a dozen companions of delegates.

Research paper thumbnail of A 5 cm (6 GHz) Multibeam Radio-Continuum Survey of the Galactic Plane -- Pilot Observations

Basic information about the structure of magnetic fields in our own and nearby galaxies can be ex... more Basic information about the structure of magnetic fields in our own and nearby galaxies can be extracted directly from radio-continuum surveys taken at two orthogonal polarizations. Recent surveys reveal magnetic structures along the Galactic plane with no counterpart in total intensity maps. This is first evidence of an intrinsic Galactic magnetic field. Its fingerprint is synchrotron emission, originating from relativistically accelerated electrons trapped in the Galactic magnetic field. They are readily identified by their well known radio spectra. Unfortunately, there is a big gap in available observational data of the Galactic plane between the frequencies 2.4 GHz (12.5 cm) and 22.8 GHz (1.3 cm). This project will fill this gap with a new radio-continuum survey at a wavelength of 5 cm (6-7 GHz) using the new multi-beam receiver at the Parkes Radio Telescope. Simultaneously this project will observe and map large and small scale structures along the Galactic plane caused by non-thermal emission mechanisms such as supernova remnants shells which evolve into chimneys and fountains. This proposal is ONLY for testing time.

Research paper thumbnail of The Effelsberg 100-m Radio Telescope: Construction and Forty Years of Radio Astronomy

The Effelsberg 100-m dish represents a major breakthrough in the technology of radio telescope co... more The Effelsberg 100-m dish represents a major breakthrough in the technology of radio telescope construction. Using new methods of computation a big step in the direction of improved surface accuracy for large structures was achieved. In conjunction with the decision to build the 100-m radio telescope the Max-Planck-Gesellschaft (MPG) founded the Max-Planck-Institute for Radio Astronomy (MPIfR) in Bonn. The MPIfR

Research paper thumbnail of Inter-Division IV-V-IX / Working Group Historic Radio Astronomy

Proceedings of the International Astronomical Union, 2008

Research paper thumbnail of DIVISION X WORKING GROUP on HISTORIC RADIO ASTRONOMY

Proceedings of the International Astronomical Union, 2010

Research paper thumbnail of A sensitive 1.5 GHz radio survey around the north ecliptic pole

The Astrophysical Journal Supplement Series, 1994

Research paper thumbnail of A 5 cm (6 GHz) Multi-beam Radio-Continuum Survey of the Galactic Plane--Pilot Observations

Basic information about the structure of magnetic fields in our own and nearby galaxies can be ex... more Basic information about the structure of magnetic fields in our own and nearby galaxies can be extracted directly from radio-continuum surveys taken at two orthogonal polarizations. Recent surveys reveal magnetic structures along the Galactic plane with no counterpart in total intensity maps. This is first evidence of an intrinsic Galactic magnetic field. Its fingerprint is synchrotron emission, originating from relativistically accelerated electrons trapped in the Galactic magnetic field. They are readily identified by their well known radio spectra. Unfortunately, there is a big gap in available observational data of the Galactic plane between the frequencies 2.4 GHz (12.5 cm) and 22.8 GHz (1.3 cm). This project will fill this gap with a new radio-continuum survey at a wavelength of 5 cm (6-7 GHz) using the new multi-beam receiver at the Parkes Radio Telescope. Simultaneously this project will observe and map large and small scale structures along the Galactic plane caused by non-thermal emission mechanisms such as supernova remnants shells which evolve into chimneys and fountains. This proposal is ONLY for testing time.

Research paper thumbnail of Cold dust in a selected sample of nearby galaxies

Research paper thumbnail of CO(J=2-1) Observations of the Edge-On Galaxy NGC4631

Proceedings of the International Astronomical Union, 1991

Research paper thumbnail of The interstellar medium of the edge-on galaxy NGC 5907: new observations in the cm- and mm-range

Astronomische Gesellschaft Abstract Series, 1995

Research paper thumbnail of Shapiro Delay in the PSR J1640+2224 Binary System

Astrophys J, 2005

We present the results of precision timing observations of the binary millisecond pulsar PSR J164... more We present the results of precision timing observations of the binary millisecond pulsar PSR J1640+2224. Combining the pulse arrival time measurements made with the Effelsberg 100 m radio telescope and the Arecibo 305 m radio telescope, we have extended the existing timing model of the pulsar to search for a presence of the effect of a general relativistic Shapiro delay in the data. At the currently attainable precision level, the observed amplitude of the effect constrains the companion mass to m2=0.15+0.08-0.05Msolar, which is consistent with the estimates obtained from optical observations of the white dwarf companion and with the mass range predicted by theories of binary evolution. The measured shape of the Shapiro delay curve restricts the range of possible orbital inclinations of the PSR J1640+2224 system to 78deg<=i<=88deg. The pulsar offers excellent prospects to significantly tighten these constraints in the near future.

Research paper thumbnail of Pulse shapes of radio pulsars at 4.85 GHz

Astronomy and Astrophysics Supplement Series, 1998

Research paper thumbnail of Polarized Radio Emission of Edge-on Galaxies Observational Results and Implications

Proceedings of the International Astronomical Union

Research paper thumbnail of Galactic and Extragalactic Magnetic Fields

Reviews in Modern Astronomy, 1995

... 1988). More recently high efficiency half-wave plates were used in the JCMT telescope for sub... more ... 1988). More recently high efficiency half-wave plates were used in the JCMT telescope for sub-mm polarimetery (Murray et al 1992). ... Surveys at 1400 MHz by Bingham (1966), andSpoelstra (1971; 1984) added new information on selected areas. ...

Research paper thumbnail of Galactic and Extragalactic Magnetic Fields

Reviews in Modern Astronomy, 1995

... 1988). More recently high efficiency half-wave plates were used in the JCMT telescope for sub... more ... 1988). More recently high efficiency half-wave plates were used in the JCMT telescope for sub-mm polarimetery (Murray et al 1992). ... Surveys at 1400 MHz by Bingham (1966), andSpoelstra (1971; 1984) added new information on selected areas. ...

Research paper thumbnail of Radio continuum observations of nearby galaxies

Monthly Notices of the Royal Astronomical Society, 1987

... Although NGC 1553 is a normal SO galaxy with no bar, it has a lens with high surface brightne... more ... Although NGC 1553 is a normal SO galaxy with no bar, it has a lens with high surface brightness and a prominent nucleus ... Both CG and NGC 4945 have nuclear H20 maser emission at least an order of magnitude greater than W49, the strongest Galactic source (Gardner & ...

Research paper thumbnail of IAU Historic Radio Astronomy Working Group. Triennial Report (2003-2006)

Research paper thumbnail of The IAU Historic Radio Astronomy Working Group. 3: Progress Report (2006-2009)

Research paper thumbnail of Formation of Molecular Gas Rings in Galaxies

Proceedings of the International Astronomical Union, 1991

Research paper thumbnail of Molecular distribution and kinematics in nearby galaxies. I. NGC 253

Astron Astrophys, 1996

The central 80"x60" of the edge-on starburst galaxy NGC 253 has been mapped in the J=2-1 line of ... more The central 80"x60" of the edge-on starburst galaxy NGC 253 has been mapped in the J=2-1 line of ^12^CO with the IRAM 30m telescope (beam width: 12"). After a Lucy deconvolution, the resolution is enhanced to ~4". CO emission is strongly concentrated toward a region elongated along the major axis with a FWHP size of 34"x11" (410pcx130pc at D=2.5Mpc). Toward the center of NGC 253, the ^12^CO(2-1) line contributes between 20% and 35% to the total measured 1.3mm "continuum" in a 50GHz wide bandpass. Position-velocity maps reveal two condensations symmetrically placed with respect to the nucleus. Distinct velocity features suggest the presence of a compact molecular spiral, although a molecular bar or ring cannot be excluded. The dynamical mass in the inner 480pc is 2.610^9^Msun_. Applying a "standard" N(H_2_)/I(CO) conversion factor of 2x10^20^cm^-2^/Kkm/s, the molecular gas mass of the central condensations would be ~3x10^8^Msun_. Other tracers of molecular mass, namely optically thin C^18^O rotational lines and the mm-wave dust continuum yield gas masses of 4x10^7^...6x10^7^Msun_. The most plausible explanation of this discrepancy is that the "standard" H_2_ mass/CO luminosity ratio, which has been derived for Galactic disk clouds, cannot be applied to the bulge region of galaxies such as NGC 253. Possible reasons are discussed in terms of excitation conditions and the influence of the stellar gravitational potential. It is not the gas mass that makes NGC 253 an outstanding galaxy but its infrared luminosity and the "star forming efficiency" L_IR_/M_gas_ of 90Lsun_/Msun_.

Research paper thumbnail of Radio Studies of Galactic Objects, Galaxies and AGNs

The Sino-German Radio Astronomy Conference was held in Xi'an between July 18th and 25th 2002. Thi... more The Sino-German Radio Astronomy Conference was held in Xi'an between July 18th and 25th 2002. This conference was also a meeting of radio astronomy in China. The partner group of Max-Plack-Institut for Radioastronomie at National Astronomical Observatories of China took the responsibility for detailed organizations. The conference was focused on "Radio studies of Galactic objects, galaxies and AGNs", with 80 partici- pants plus the 6 helpers. Most radio astronomers in China together with about 30 students enjoyed the fruitful discussions with 9 German senior scientists and 6 famous experts from other countries. In addition, the his- torical sites and culture environments specifically in Xi'an also attracted a dozen companions of delegates.

Research paper thumbnail of A 5 cm (6 GHz) Multibeam Radio-Continuum Survey of the Galactic Plane -- Pilot Observations

Basic information about the structure of magnetic fields in our own and nearby galaxies can be ex... more Basic information about the structure of magnetic fields in our own and nearby galaxies can be extracted directly from radio-continuum surveys taken at two orthogonal polarizations. Recent surveys reveal magnetic structures along the Galactic plane with no counterpart in total intensity maps. This is first evidence of an intrinsic Galactic magnetic field. Its fingerprint is synchrotron emission, originating from relativistically accelerated electrons trapped in the Galactic magnetic field. They are readily identified by their well known radio spectra. Unfortunately, there is a big gap in available observational data of the Galactic plane between the frequencies 2.4 GHz (12.5 cm) and 22.8 GHz (1.3 cm). This project will fill this gap with a new radio-continuum survey at a wavelength of 5 cm (6-7 GHz) using the new multi-beam receiver at the Parkes Radio Telescope. Simultaneously this project will observe and map large and small scale structures along the Galactic plane caused by non-thermal emission mechanisms such as supernova remnants shells which evolve into chimneys and fountains. This proposal is ONLY for testing time.

Research paper thumbnail of The Effelsberg 100-m Radio Telescope: Construction and Forty Years of Radio Astronomy

The Effelsberg 100-m dish represents a major breakthrough in the technology of radio telescope co... more The Effelsberg 100-m dish represents a major breakthrough in the technology of radio telescope construction. Using new methods of computation a big step in the direction of improved surface accuracy for large structures was achieved. In conjunction with the decision to build the 100-m radio telescope the Max-Planck-Gesellschaft (MPG) founded the Max-Planck-Institute for Radio Astronomy (MPIfR) in Bonn. The MPIfR

Research paper thumbnail of Inter-Division IV-V-IX / Working Group Historic Radio Astronomy

Proceedings of the International Astronomical Union, 2008

Research paper thumbnail of DIVISION X WORKING GROUP on HISTORIC RADIO ASTRONOMY

Proceedings of the International Astronomical Union, 2010

Research paper thumbnail of A sensitive 1.5 GHz radio survey around the north ecliptic pole

The Astrophysical Journal Supplement Series, 1994

Research paper thumbnail of A 5 cm (6 GHz) Multi-beam Radio-Continuum Survey of the Galactic Plane--Pilot Observations

Basic information about the structure of magnetic fields in our own and nearby galaxies can be ex... more Basic information about the structure of magnetic fields in our own and nearby galaxies can be extracted directly from radio-continuum surveys taken at two orthogonal polarizations. Recent surveys reveal magnetic structures along the Galactic plane with no counterpart in total intensity maps. This is first evidence of an intrinsic Galactic magnetic field. Its fingerprint is synchrotron emission, originating from relativistically accelerated electrons trapped in the Galactic magnetic field. They are readily identified by their well known radio spectra. Unfortunately, there is a big gap in available observational data of the Galactic plane between the frequencies 2.4 GHz (12.5 cm) and 22.8 GHz (1.3 cm). This project will fill this gap with a new radio-continuum survey at a wavelength of 5 cm (6-7 GHz) using the new multi-beam receiver at the Parkes Radio Telescope. Simultaneously this project will observe and map large and small scale structures along the Galactic plane caused by non-thermal emission mechanisms such as supernova remnants shells which evolve into chimneys and fountains. This proposal is ONLY for testing time.

Research paper thumbnail of Cold dust in a selected sample of nearby galaxies

Research paper thumbnail of CO(J=2-1) Observations of the Edge-On Galaxy NGC4631

Proceedings of the International Astronomical Union, 1991

Research paper thumbnail of The interstellar medium of the edge-on galaxy NGC 5907: new observations in the cm- and mm-range

Astronomische Gesellschaft Abstract Series, 1995

Research paper thumbnail of Shapiro Delay in the PSR J1640+2224 Binary System

Astrophys J, 2005

We present the results of precision timing observations of the binary millisecond pulsar PSR J164... more We present the results of precision timing observations of the binary millisecond pulsar PSR J1640+2224. Combining the pulse arrival time measurements made with the Effelsberg 100 m radio telescope and the Arecibo 305 m radio telescope, we have extended the existing timing model of the pulsar to search for a presence of the effect of a general relativistic Shapiro delay in the data. At the currently attainable precision level, the observed amplitude of the effect constrains the companion mass to m2=0.15+0.08-0.05Msolar, which is consistent with the estimates obtained from optical observations of the white dwarf companion and with the mass range predicted by theories of binary evolution. The measured shape of the Shapiro delay curve restricts the range of possible orbital inclinations of the PSR J1640+2224 system to 78deg<=i<=88deg. The pulsar offers excellent prospects to significantly tighten these constraints in the near future.