| 1. |
- Bartel, N., et al.
(författare)
-
The Compact Radio Source 2021+614 : Simultaneous 2.3 and 8.3 GHz Mark III VLBI Observations
- 1984
-
Ingår i: Astrophysical Journal. - Philadelphia, PA : Institute of Physics Publishing (IOPP). - 0004-637X .- 1538-4357. ; 279:1, s. 116-121
-
Tidskriftsartikel (refereegranskat)abstract
- Second-epoch VLBI observations of the flat-spectrum radio source 2021+614 made simultaneously at 2.3 and 8.3 GHz with the Mark III system are reported. The maps derived from these observations reveal a complex, frequency-dependent radio structure on the milliarcsecond scale. The object has four nearly collinear components oriented at a position angle of about 35 degrees and embedded in an extended region. Two of these are optically thin, one has a flat spectrum, and the other appears to be synchrotron self-absorbed in the frequency range 2.3-8.3 GHz. No significant structural variation is found at either frequency between epochs separated by about three years. The formal estimate of the transverse velocity between two components, one with a flat and the other with an inverted spectrum, is v/c = 0.7 + or - 2.3. Remarkable similarities between 2021+614 and the unusual source 0316+413 are discussed.
|
|
| 2. |
- Blomqvist, Jan Einar
(författare)
-
Educating entrepreneurs for handling the innovation process with new product development in industry or in own formed company
- 1989
-
Ingår i: SEFITALIA89. - Neapel : University of Naples. ; , s. 15-21
-
Konferensbidrag (refereegranskat)abstract
- At Halmstad University College on the west coast of Sweden, we have a unique education in innovation and entrepreneurial engineering. The three year program provides the candidates with a braod technical economical education with special emphasize on handling the innovation process and running new product development projects. This is the summing up og 10 years experience during which 140 innovation engineers have been graduated.
|
|
| 3. |
|
|
| 4. |
- Bååth, L.B. 1948-
(författare)
-
High Resolution Observations of Low Frequency Variables at 932 MHz
- 1987
-
Ingår i: The Impact of VLBI on Astrophysics and Geophysics. - Dordrecht : Kluwer Academic Publishers. - 902772704X - 9027727058 ; , s. 117-118
-
Bokkapitel (refereegranskat)abstract
- Fifteen sources known to be varying at low frequencies have been observed at six epochs during 1983–84 with a global VLBI array. Some of the sources show structural variations similar to the superluminals. Beaming effect may therefore play an important role at low as well as at higher frequencies.
|
|
| 5. |
- Bååth, L.B. 1948-, et al.
(författare)
-
High Resolution Observations of the QSO 3C 345 at 1.3 centimeters
- 1981
-
Ingår i: Astrophysical Journal. - Philadelphia, PA : Institute of Physics Publishing (IOPP). - 0004-637X .- 1538-4357. ; 243, s. L123-L126
-
Tidskriftsartikel (refereegranskat)abstract
- High-resolution VLBI observations made at a frequency of 22.235 GHz of the quasar 3C 345 are discussed. Antennas located at the Crimean Astrophysical Observatory, USSR; Onsala, Sweden; Effelsberg, West Germany; and the Haystack Observatory, Massachusetts were employed at 4-min integration times to provide baselines ranging up to 5.5 x 10 to the 8th wavelengths. About 40% of the total flux density of 7.85 Jy, observed in November 1977, and 8.05 Jy, observed in October 1978, is found to originate in an unresolved component of the quasar core in a region less than 0.1 milliarcsec in diameter. The elongated jet-like component of the quasar is observed to contain several peaks of emission extending up to 6 milliarsec from the core which decreased in extent between the two observations.
|
|
| 6. |
- Bååth, L.B. 1948-
(författare)
-
Mapping in Practice
- 1989
-
Ingår i: Very Long Baseline Interferometry. - Dordrecht : Kluwer Academic Publishers. - 9789401075954 - 9789400924284 - 0792303768 ; , s. 199-230
-
Bokkapitel (refereegranskat)abstract
- The purpose of this lecture is to introduce the VLBI user to the practical details of mapping radio sources. I will concentrate on data processing and mapping with the AIPS (Thompson and D’Addario, 1982)-package. Other data reduction systems do exist, e.g. the Caltech-package and OLAF. These differ from AIPS mostly in the strategy for reaching the final and “best” map. It is more important to know the method and to be careful than what reduction procedure is used.
|
|
| 7. |
- Bååth, L.B. 1948-
(författare)
-
Superluminal Motion in CTA 102
- 1987
-
Ingår i: Superluminal Radio Sources. - Cambridge : Cambridge University Press. - 052134560X ; , s. 206-210
-
Bokkapitel (refereegranskat)
|
|
| 8. |
|
|
| 9. |
- Bååth, L.B. 1948-, et al.
(författare)
-
The Radio Fine Structure of the BL Lacertae Objects AO0235+164, 0735+178, BL Lac, 1749+701, Mk 421 and 3C 66 A at 5 GHz
- 1981
-
Ingår i: Astronomy and Astrophysics. - Les Ulis : EDP Sciences. - 0004-6361 .- 1432-0746. ; 96:1-2, s. 316-324
-
Tidskriftsartikel (refereegranskat)abstract
- Very long baseline interferometer observations at 4997 MHz (lambda = 6 cm) on European and intercontinental baselines with lengths up to 1.35 108lambda have been used to probe the milliarc s structure of the BL Lacertae objects AO 0235+164, 0735+178, BL Lac, 1749+701, Mk 421, and 3C 66A. Two sets of observations are reported, made in November 1978 and March 1979. AO 0235+164 and 0735+178 both showed structures consisting of a very bright, unresolved core and a jet-like component extending ˜5".4 10-3 along position angle ˜20° and ˜4".2 10-3 along position angle ˜45°, respectively. AO 0235+164 contained more than 98% of the total flux density within a diameter of ≲ 36" 10-3. BL Lac, 1749+701 and Mk 421 all showed evidence for a complex structure of several components, including an unresolved core. 3 C 66A was elongated along position angle ˜ -45°.
|
|
| 10. |
- Bååth, L.B. 1948-, et al.
(författare)
-
Time-Dependent Radio Fine Structure of the Compact Sources NRAO 150 and 4C 39.25
- 1980
-
Ingår i: Astronomy and Astrophysics. - Les Ulis : EDP Sciences. - 0004-6361 .- 1432-0746. ; 86:3, s. 364-372
-
Tidskriftsartikel (refereegranskat)abstract
- Very long baseline interferometer observations at 7.85 GHz have been used to probe the milliarcsecond structure of the unidentified, very compact radio source NRAO 150 and QSO 4 C 39.25. NRAO 150 exhibited no structural variations from 1972 to the end of 1974. A model with two circular Gaussian components fits the data well. NRAO 150 had a flux density of 7.6 plus or minus 0.5 Jy in the compact component; 4 C 39.25 showed a two-component structure, the components having a separation of (2.02 plus or minus 0.05 arc sec) x 10 to the -3rd power. The upper bound on the speed of transverse separation is 0.0001 arc sec per year or less than 2.7 c. From the spectrum there are also indications of a third, larger component.
|
|
