Spectral atlases of the Sun from 3980 to 7100 Å at the center and at the limb

In this work, we present digital and graphical atlases of spectra of both the solar disk-center and of the limb near the Solar poles using data taken at the UTS-IAP & RIAAM (the University of Tabriz Siderostat, telescope and spectrograph jointly developed with the Institut d’Astrophysique de Paris and Research Institute for Astronomy and Astrophysics of Maragha). High resolution and high signal-to-noise ratio (SNR) CCD-slit spectra of the sun for 2 different parts of the disk, namely for μ=1.0 (solar center) & for μ=0.3 (solar limb) are provided and discussed. While there are several spectral atlases of the solar disk-center, this is the first spectral atlas ever produced for the solar limb at this spectral range. The resolution of the spectra is about R～70?000 (Δλ～0.09 Å) with the signal-to-noise ratio (SNR) of 400–600. The full atlas covers the 3980 to 7100 Å spectral regions and contains 44 pages with three partial spectra of the solar spectrum put on each page to make it compact. The difference spectrum of the normalized solar disk-center and the solar limb is also included in the graphic presentation of the atlas to show the difference of line profiles, including far wings. The identification of the most significant solar lines is included in the graphic presentation of the atlas. Telluric lines are producing a definite signature on the difference spectra which is easy to notice. At the end of this paper we present only two sample pages of the whole atlas while the graphic presentation of the whole atlas along with its ASCII file can be accessed via the ftp server of the CDS in Strasbourg via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via this link: http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/other/ApSS.     

Observations of Ultraluminous IRAS Galaxies at 20cm

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

Nonsemisimple 1∶1 resonance at an equilibrium

Consider a Hamiltonian system of two degrees of freedom at an equilibrium. Suppose that the linearized vectorfield has eigenvaluesi,i,–i,–i ( , >0) and is not semisimple. In this paper we discuss the real normalization of the Hamiltonian function of such a system. We normalize the Hamiltonian up to 4th order and show how to compute its coefficients. For the planar restricted three body problem atL ₄ the coefficient that plays an important role in the investigation of the qualitative behaviour of periodic solutions near the equilibrium is explicitly calculated.     

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…     

Solar Magnetism and the Activity Telescope at HSOS

A new solar telescope system is described, which has been operating at Huairou Solar Observing Station (HSOS), National Astronomical Observatories, Chinese Academy of Sciences (CAS), since the end of 2005. This instrument, the Solar Magnetism and Activity Telescope (SMAT), comprises two telescopes which respectively make measurements of full solar disk vector magnetic field and Hα observation. The core of the full solar disk video vector magnetograph is a birefringent filter with 0.1  bandpass, installed in the tele-centric optical system of the telescope. We present some preliminary observational results of the full solar disk vector magnetograms and Hα filtergrams obtained with this telescope system.     

Prominence hydrogen lines at 10–20 microns

An analysis of prominence hydrogen lines is presented in the spectral band 10–20 . The results are consistent with earlier work.Operated by the Association of Universities for Research in Astronomy, Inc., under contrast AST 84-18716 with the National Science Foundation.     

Follow-Up Spectroscopy of Supernovae at Bisei Astronomical Observatory

1　Ｐｕｒｐｏｓｅｓｏｆｆｏｌｌｏｗ ｕｐｓｐｅｃｔｒｏｓｃｏｐｙＴｈｅｐｕｒｐｏｓｅｓｏｆｏｕｒｆｏｌｌｏｗ ｕｐｓｐｅｃｔｒｏｓｃｏｐｙｏｆｓｕｐｅｒｎｏｖａｅａｒｅａｓｆｏｌｌｏｗｓ ;●　Ｉｄｅｎｔｉｆｉｃａｔｉｏｎｏｆｔｈｅｔｙｐｅａｎｄｐｈａｓｅ (ｄａｔｅｓｂｅｆｏｒｅ/ａｆｔｅｒｍａｘｉｍｕｍ)ｏｆｎｅｗｌｙｄｉｓｃｏｖｅｒｅｄｓｕｐｅｒｎｏｖａａｔａｎｅａｒｌｙｓｔａｇｅ .Ｉｄｅｎｔｉｆｉｃａｔｉｏｎｏｆｔｙｐｅａｎｄｐｈａｓｅｓｈｏｕｌｄｂｅｄｏｎｅａｓｅａｒｌｙａｓｐｏｓｓｉｂｌｅ.…     

Solar S-bursts at Frequencies of 10 – 30 MHz

Solar S-bursts observed by the radio telescope UTR-2 in the period 2001 – 2002 are studied. The bursts chosen for a detailed analysis occurred in the periods 23 – 26 May 2001, 13 – 16 and 27 – 39 July 2002 during three solar radio storms. More than 800 S-bursts were registered in these days. Properties of S-bursts are studied in the frequency band 10 – 30 MHz. All bursts were always observed against a background of other solar radio activity such as type III and IIIb bursts, type III-like bursts, drift pairs and spikes. Moreover, S-bursts were observed during days when the active region was situated near the central meridian. Characteristic durations of S-bursts were about 0.35 and 0.4 – 0.6 s for the May and July storms, respectively. For the first time, we found that the instantaneous frequency width of S-bursts increased with frequency linearly. The dependence of drift rates on frequency followed the McConnell dependence derived for higher frequencies. We propose a model of S-bursts based on the assumption that these bursts are generated due to the confluence of Langmuir waves with fast magnetosonic waves, whose phase and group velocities are equal.     

Site testing at Muztagh-ata site Ⅱ:seeing statistics

In this article,we present a detailed analysis of the statistical properties of seeing for the Muztaghata site which is a candidate site for hosting the future Chinese Large Optical/infrared Telescope(LOT)project.The measurements were obtained with differential image motion monitors(DIMMs) from April2017 to November 2018 at different heights during different periods.The median seeings at 11 m and6 m are very close but significantly different from that on the ground.We mainly analyzed the seeing at11 m monthly and hourly,having found that the best season for observing was from late autumn to early winter and seeing tended to improve during the night only in autumn.The analysis of the dependence on temperature inversion,wind speed and direction also was made and the best meteorological conditions for seeing are given.     

Chromospheric Internetwork Oscillations at Various Locations of the Quiet Sun

We analyze oscillation behaviours in chromospheric internetwork regions using spectral observations of the CⅡ1334 A line obtained with the Solar Ultraviolet Measurements of Emitted Radiation spectrograph (SUMER) aboard Solar and Heliospheric Observatory (SOHO). Three areas, 26 ×120arcsec2 each, at the various latitudes from the disk center to the north polar coronal hole, were rastered with a cadence of about 40-60 s in the solar minimum year. We obtained the time evolution of two-dimensional (2D) line intensity, continuum and line core shift. The continuum and the line shift show -3 min chromospheric oscillations in the internetwork regions underlying the coronal hole as well as at the disk center. We find that the CⅡ1334A line shift oscillates with an average speed of -1.7 km s-1, independent of the latitude, while its coherent scale decreases with latitude. On the other hand, the oscillation amplitude of the continuum around the 1334 A and the phase delay between the Doppler shift and continuum sli     

Can non-linear structure form at the era of decoupling?

The effects of large-scale fluctuations on small-scale isothermal modes at the epoch of recombination are analysed. We find the following. (a) Albeit the fact that primordial fluctuations were at this epoch still well in the linear regime, a significant non-linear radiation hydrodynamic interaction could have taken place. (b) Short-wavelength isothermal fluctuations are unstable. Their growth rate is an exponential function of the amplitude of the large-scale fluctuations and is therefore very sensitive to the initial conditions. (c) The observed cosmic microwave background radiation (CMBR) fluctuations are of order of the limit above which the effect should be significant. Thus, depending on their exact value, the effect may be negligible or lead to structure formation out of the isothermal fluctuations within the period of recombination. (d) If the cosmological parameters are within the prescribed regime, the effect should be detectable through induced deviations in the Planck spectrum. (e) The sensitivity of the effect to the initial conditions provides a tool to set limits on various cosmological parameters with emphasis on the type and amplitude of the primordial fluctuation spectrum. (f) Under proper conditions, the effect may be responsible for the formation of sub-globular-cluster sized objects at particularly high redshifts. (g) Under certain circumstances, it can also affect horizon-sized large-scale structure.     

Does Magnetic Flux Submerge at Flux Cancelation Sites?

Simultaneous measurements of the magnetic fields in the photosphere and chromosphere were used to investigate if magnetic flux is submerging at sites between adjacent opposite polarity magnetic network elements in which the flux is observed to decrease or `cancel'. These data were compared with chromospheric and coronal intensity images to establish the timing of the emission structures associated with these magnetic structures as a function of height. We found that most of the cancelation sites show either that the bipole is observed longer in the photosphere than in the chromosphere and corona (44%) or that the timing difference of the disappearance of the bipole between these levels of the atmosphere is unresolved. The magnetic axis lengths of the structures associated with the cancelation sites are on average slightly smaller in the chromosphere than the photosphere. These observations suggest that magnetic flux is retracting below the surface for most, if not all, of the cancelation sites studied.     

Laboratory planetary physics using intense heavy ion beams at the Facility for Antiprotons and Ion Research at Darmstadt: the HEDgeHOB collaboration

Development of ultra-high power lasers has lead to the very interesting and important field of Laboratory Astrophysics. Recent progress and expected near future developments in the technology of strongly bunched intense particle beams has opened up the possibility of studying planetary interiors in the laboratory which hopefully will eventually converge in the new field of Laboratory Planetary Physics. GSI Helmholzzentrum für Schwerionenforschung, Darmstadt is a well known laboratory worldwide due to its unique particle accelerator facilities. Construction of the new huge accelerator complex, the Facility for Antiprotons and Ion Research (FAIR), will substantially improve the existing capabilities of the GSI. A dedicated program named, HEDgeHOB, that aims to study different problems in High Energy Density (HED) Physics at the FAIR facility, has been proposed. One of these proposed experiments LAPLAS (LAboratory PLAnetary Science), aim to study materials at extreme conditions as relevant for the interiors of giant planets. In this paper we present simulation results that show that various regions of the high-pressure phase diagram of water can be probed within the LAPLAS experiments. For instance, the plasma and the superionic phase are predicted to occur in the interior of water-rich planets such as Uranus and Neptune as well as in extrasolar planets such as GJ 436b.     

Site-testing at Muztagh-ata site Ⅰ:ground meteorology and sky brightness

Site-testing is crucial for achieving the goal of scientific research and analysis of meteorological and optical observing conditions,one of the associated basic tasks.As one of three potential sites to host the 12-meter Large Optical/infrared Telescope(LOT),the Muztagh-ata site,which is located on the Pamir Plateau in Xinjiang,in west China,began its site-testing task in the spring of 2017.In this paper,we firstly start with an introduction to the site and then present a statistical analysis of the ground-level meteorological properties such as air temperature,barometric pressure,relative humidity,and wind speed and direction,recorded by an automatic weather station with standard meteorological sensors for a two-year duration.We also show the monitoring results of sky brightness during this period.     

Biographical index “Astronomers of Ukraine” at the UkrVO portal

The new electronic database developed by the authors and titled “Astronomers of Ukraine” is described as a source of the main biographical data on astronomers of Ukraine from the 15th century until the beginning of the 21st century. The database is an upgrading component of the Ukrainian Virtual Observatory portal and contains the main biobibliographical data and papers concerning astronomers of Ukraine, as well as links to their publications. The existing biographical sources about astronomers in the world are discussed briefly. A list of the principal publications about astronomers of Ukraine is given.     

Modeling of Hα Eruptive Events Observed at the Solar Limb

We present spectra and slit-jaw images of limb and on-disk eruptive events observed with a high temporal resolution by the Ond?ejov Observatory optical spectrograph. Analysis of the time series of full width at half-maximum (FWHM) in Hα, Hβ, and radio and soft X-ray (SXR) fluxes indicates two phenomenologically distinct types of observations which differ significantly in the timing of FWHM and SXR/radio fluxes. We investigated one such unusual case of a limb eruptive event in more detail. Synthesis of all observed data supports the interpretation of the Hα broadening in the sense of regular macroscopic plasma motions, contrary to the traditional view (emission from warm dense plasma). The timing and observed characteristics indicate that we may have actually observed the initiation of a prominence eruption. We test this scenario via modeling of the initial phase of the flux rope eruption in a magnetohydrodynamic (MHD) simulation, calculating subsequently – under some simplifying assumptions – the modeled Hα emission and spectrum. The modeled and observed data correspond well. Nevertheless, the following question arises: To what extent is the resulting emission sensitive to the underlying model of plasma dynamics? To address this issue, we have computed a grid of kinematic models with various arbitrary plasma flow patterns and then calculated their resulting emission. Finally, we suggest a diagnostics based on the model and demonstrate that it can be used to estimate the Alfvén velocity and plasma beta in the prominence, which are otherwise hard to obtain.     

Site-testing at Muztagh-ata site Ⅲ:temperature inversion in surface-layer atmosphere

In this article,we present detailed seasonal,monthly and daily statistics of temperature difference in the surface layer at the Muztagh-ata site based on the temperature measurements at two heights of 2 m and6 m.We find that temperature inversion occurs frequently at our site during nighttime,especially during the cold season.Strong temperature inversion always represents stable atmospheric turbulence,which is crucial for an optical observatory.By analyzing the behavior of temperature inversion and its correlation with wind and cloud amount,one conclusion can be made that radiation inversion is the main reason for the existence of temperature inversion in the surface-layer at the Muztagh-ata site.     

Characteristics and Performance of the CCD Photometric System at Lulin Observatory

The Lulin One-meter Telescope at Lulin Observatory in Taiwan started open-use observations in January 2003. In order to evaluate the performance of the CCD photometric system, the characteristics and quality of the site, we obtained data of photometric standards as well as calibration data from February to November 2004. We report here the results of our analysis including the gain, readout noise, dark current and linearity of the CCD camera, and transformation coefficients, total throughputs, night sky brightnesses and limiting magnitudes for UBVRI bands.