Radio Observations of Sgr B2

1 INTRODUCTIONFor the behavior of a molecular cloud in subsonic collision with another, Mao et al. (1992)have obtained simplified one-dimension traveling wave solutions for a plane-parallel s1ab. Chang-ing the sign in the transformation of variables in their case, we have the fOllowing results,1 rP = 2 l W op -- 1, (1)1 r =v = -- j W -- ry 1. (2)2 {V(N M)' 2z 2t -- W 1. (2)In Eq. (1), p increases with increasing t. Instability is expected to occur in strongly perturbedmolecular…     

Observations of Ellerman bombs in H α

A developing active region near the center of the solar disk was observed for 80 min at the center and the wings of H. Ellerman bombs lying both below an Arch Filament System and near sunspots were studied at H - 1.0 Å and H - 0.75 Å. We determined their average contrast, lifetime, size and we studied their flux as a function of time. We found evidence that the size of Ellerman bombs increases with height. The time curves of flux provide evidence for both impulsive and gradual energy release. Under the AFS the Ellerman bombs form a cellular pattern with a characteristic size of 3.1 × 10³ km. Fifty percent of the bombs appear and disappear in pairs, possibly associated with bipolar emerging magnetic flux tubes.     

Recent Observations of PMS δ Scuti Stars

We present time series observations of the intermediate mass Pre-Main Sequence star H254 belonging to the young star cluster IC 348 and of the Herbig Ae star V351 Ori.Both these stars present light variation on short time scale (a few hours) typical of the Scuti pulsation. The new data are briefly described together with the plan for future observational campaigns on PMS Scuti stars.     

VIBI Observations of Two Quasars at 1.3cm

1　ＩｎｔｒｏｄｕｃｔｉｏｎＴｈｅｏｂｊｅｃｔｓ ,0 748 1 2 6ａｎｄ 2 2 5 1 1 5 8( 3Ｃ45 4 3) ,ａｒｅｑｕａｓａｒｓ.Ｔｈｅｙａｌｌｈａｖｅａｎｏｐｔｉｃａｌｌｙｂｒｉｇｈｔｎｕｃｌｅｕｓ.Ｔｈｅｃｏｍｐａｃｔｎｕｃｌｅｉ,ｅｍｉｔｔｉｎｇｓｔｒｏｎｇｒａｄｉｏｒａｄｉａｔｉｏｎａｔｃｅｎｔｅｒｍｅｔｅｒｗａｖｅｌｅｎｇｔｈ ,ａｒｅｔｙｐｉｃａｌＡＧＮｓ .ＴｈｅｒａｄｉｏｅｍｉｓｓｉｏｎｒｅｇｉｏｎｉｎｔｈｅＡＧＮｓｉｓｖｅｒｙｓｍａｌｌｉｎｓｉｚｅＷｅｈａｖｅｃａｒｒｉｅｄｏｕｔｓｎａｐｓｈｏｔ…     

Milestones in the Observations of Cosmic Magnetic Fields

Magnetic fields are observed everywhere in the universe. In this review, we concentrate on the observational aspects of the magnetic fields of Galactic and extragalactic objects. Readers can follow the milestones in the observations of cosmic magnetic fields obtained from the most important tracers of magnetic fields, namely, the star-light polarization, the Zeeman effect, the rotation measures (RMs, hereafter) of extragalactic radio sources, the pulsar RMs, radio polarization observations, as well as the newly implemented sub-mm and mm polarization capabilities. The magnetic field of the Galaxy was first discovered in 1949 by optical polarization observations. The local magnetic fields within one or two kpc have been well delineated by starlight polarization data. The polarization observations of diffuse Galactic radio background emission in 1962 confirmed unequivocally the existence of a Galactic magnetic field. The bulk of the present information about the magnetic fields in the Galaxy comes from anal     

Optical Photometric Observations of γ-Ray Loud Blazars

We report results of our optical photometric observations of ten gammaray loud blazers, namely: 0219 428 (3C66A), PKS 0420-014 (OA 129), S5 0716 714,0754 100 (OI 090.4), 0827 243 (OJ248), 1652 398 (Mrk 501), 2200 420 (BL Lacertae), 2230 114 (CTA 102), 2251 158 (3C 454.3) and 2344 514. The observations were carried out in September-October, 2000 using the 70 cm optical telescope at Abstumani Observatory, Georgia. We found intra-day variations in 0420-014,S5 0716 714, BL Lacertae and CTA 102. A variation of 0.3 magnitude over a timescale of about 3 hours was observed in the R passband in BL Lacertae on JD 2451827.We did not detect any variation in 3C 66A, Mrk 501, or 3C 454.3 during our observations. Nor did we detect any clear evidence of variation in 1ES 2344 514 during our two weeks‘ observing run of the TeV gamma-ray source.     

Observations of Ultraluminous IRAS Galaxies at 20cm

1　ＩｎｔｒｏｄｕｃｔｉｏｎＵｌｔｒａｌｕｍｉｎｏｕｓｆａｒ ｉｎｆｒａｒｅｄ (ＵＦＩＲ) ｇａｌａｘｉｅｓａｒｅｏｎｅｏｆｔｈｅｉｍｐｏｒｔａｎｔｄｉｓｃｏｖｅｒｉｅｓｍａｄｅｂｙＩ ＲＡＳ .Ｔｈｅｌｕｍｉｎｏｓｉｔｉｅｓｏｆｔｈｅｓｅｇａｌａｘｉｅｓ,>1 0 12 Ｌ⊙ ,ａｒｅ 2ｔｏ 3ｏｒｄｅｒｓｏｆｍａｇｎｉｔｕｄｅｈｉｇｈｅｒｔｈａｎｔｈｏｓｅｏｆｍｏｓｔｏｆｓｐｉｒａｌｇａｌａｘｉｅｓ,ｔｏｔｈｅｌｕｍｉｎｏｓｉｔｙｄｏｍａｉｎｏｆｑｕａｓａｒｓ .Ｔｈｅｓｏｕｒｃｅｏｆｅｎｅｒｇｙｆｏｒｓｕｃｈｇ…     

Optical Photometric Observations of 7-Ray Loud Blazars

We report results of our optical photometric observations of ten gamma-ray loud blazers, namely: 0219+428 (3C66A), PKS 0420-014 (OA 129), S5 0716+714, 0754+100 (OI 090.4), 0827+243 (OJ248), 1652+398 (Mrk 501), 2200+420 (BL Lacertae), 2230+114 (CTA 102), 2251+158 (3C 454.3) and 2344+514. The observations were carried out in September-October, 2000 using the 70 cm optical telescope at Abstumani Observatory, Georgia. We found intra-day variations in 0420-014, S5 0716+714, BL Lacertae and CTA 102. A variation of 0.3 magnitude over a time scale of about 3 hours was observed in the R passband in BL Lacertae on JD 2451827. We did not detect any variation in 3C 66A, Mrk 501, or 3C 454.3 during our observations. Nor did we detect any clear evidence of variation in 1ES 2344+514 during our two weeks' observing run of the TeV gamma-ray source.     

Photographic Observations of the July α-Capricornids Fireball

A bright fireball (TN920729) of minus-ninth absolute magnitude flew above Dushanbe (Tajikistan) at 22:12 UT on the night of July 29/30, 1992, and was photographed at two observatories (Gissar and Sanglok) of the Academy of Sciences of Tajikistan. The length of the photographed portion of the fireball trajectory and the luminous duration were equal to 40.4 km and 1.98 s, respectively. The coordinates of the radiant, velocity, and orbital elements of the fireball were determined. The fireball was found to belong to the -Capricornids shower. The mass and density of the fireball progenitor were inferred from photometric measurements of the plates and found to be equal to 0.574 kg and 2 g/cm³, respectively.     

Spectral lags of flaring events in LS I+61?303 from RXTE Observations

This work reports the first discovery of(negative) spectral lags in X-ray emission below 10 ke V from the gamma ray binary LS I+61?303 during large flaring episodes using Rossi X-ray Timing Explorer(RXTE) observations. It is found from the RXTE data that during the flares, low energy(3–5 ke V) variations lead the higher energy(8–10 ke V) variations by a few tens of seconds whereas no significant time lag is observed during the non-flaring states. The observed spectral lag features for flaring events suggest that inverse Compton scattering may be operating, at least in some part of the system. Another possibility is that the sites of particle acceleration may be different for flaring and non-flaring events such as in the microquasar model, in which the flaring radiation may come from hot spots sitting above the black hole while steady state emissions are due to the jets.     

Observations of the limb effect in potassium λ7699

Center-to-limb observations of the Ki 7699 line made on 30 days over a five-year period using the McMath-Pierce Solar Telescope at Kitt Peak are presented. Both a relative and absolute limb effect have been derived from the data. Our determination of the limb effect in Ki 7699 shows a linear increase to the limb amounting to about 40 m s^–1.Operated by the Association of Universities for Research in Astronomy, Inc. (AURA) under cooperative agreement with the National Science Foundation.     

Observations of ICMEs and ICME-like Solar Wind Structures from 2007 – 2010 Using Near-Earth and STEREO Observations

Solar Physics - The generally low interplanetary magnetic field magnitude around the minimum between Solar Cycles 23 and 24 (SC 23/24 minimum) allows us to identify weak and small solar wind...     

XMM-Newton Observations of MCG-6-30-15

1　RelativisicallyBroadenedFeKαLinesTheFeKαlineat～ 6.4keV ,whichisobservedinmanyActiveGalacticNuclei (AGN)aswellasingalacticblackholecandidates,ismainlyproducedbyfluorescence ,i.e.,ahardphoton produced ,e .g .,byComptonizationinanaccretiondiskcorona isabsorbedbytheK shellofanironatomintherelativelycoldmaterialinthethinaccretiondisk .NotethatinthecontextoftheX rayemissionfromSeyfertgalaxies ,“cold”meanstemperatureswheretheionizationstateofironisFexorless,i.e.,onlyoutershellelectrons…     

Surface-Focused Seismic Holography of Sunspots: I. Observations

We present a comprehensive set of observations of the interaction of p-mode oscillations with sunspots using surface-focused seismic holography. Maps of travel-time shifts, relative to quiet-Sun travel times, are shown for incoming and outgoing p modes as well as their mean and difference. We compare results using phase-speed filters with results obtained with filters that isolate single p-mode ridges, and we further divide the data into multiple temporal frequency bandpasses. The f mode is removed from the data. The variations of the resulting travel-time shifts with magnetic-field strength and with the filter parameters are explored. We find that spatial averages of these shifts within sunspot umbrae, penumbrae, and surrounding plage often show strong frequency variations at fixed phase speed. In addition, we find that positive values of the mean and difference travel-time shifts appear exclusively in waves observed with phase-speed filters that are dominated by power in the low-frequency wing of the p ₁ ridge. We assess the ratio of incoming to outgoing p-mode power using the ridge filters and compare surface-focused holography measurements with the results of earlier published p-mode scattering measurements using Fourier?–?Hankel decomposition.     

Seven-frequency VLBI Observations of the GHz-Peaked-Spectrum Source OQ 208

We present quasi-simultaneous VLBI images of the GHz-Peaked-Spectrum radio source OQ 208 obtained with the Very Long Baseline Array at 1.4,1.7,2.3,5.0,8.4,15.4GHz and the European VLBI Network at 6.7 GHz.The low frequency(1.4,1.7 and 2.3GHz)ob- servations reveal a weak and extended steep-spectrum component at about 30mas away at position angle-110°,which may be a remnant emission.The radio structure of OQ 208 con- sists of two mini-lobes at 5.0,6.7,8.4 and 15.4 GHz.Our spectral analysis further confirms that the southwest lobe undergoes free-free absorption and finds that the free-free absorption is stronger in the inner region.By fitting the 8.4 GHz images from 1994 to 2005,we obtain a separation speed of 0.031±0.006 mas yr~(-1)between the two mini-lobes.This indicates a jet proper motion of 0.105±0.020 c and a kinematic age of 219±42 yr for the radio source.     

Observations of aδ Scuti-like pulsator: HR 7222

Visual and blue band photometric observations of the Scuti-type variable have been carried out. It has been found that LT Vul pulsates in the radial fundamental mode. Higher overtones such as third andn > 3 overtones have also been detected.     

The Optical Observations of The Collisions of Comet Shoemaker-Levy 9 with Jupiter

In this paper,we present the main optical observation results of the collisions of comet Shoemaker-Levy 9 and Jupiter at Shanghai Observatory of China.     

Simultaneous Observations of the Chromosphere with TRACE and SUMER

Using mainly the 1600 Å continuum channel and also the 1216 Å Lyman-α channel (which includes some UV continuum and C iv emission) aboard the TRACE satellite, we observed the complete lifetime of a transient, bright chromospheric loop. Simultaneous observations with the SUMER instrument aboard the SOHO spacecraft revealed interesting material velocities through the Doppler effect existing above the chromospheric loop imaged with TRACE, possibly corresponding to extended nonvisible loops, or the base of an X-ray jet.