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1.
The original temporal analysis of a 12 night spectral timeseries of WR-134 has been found to be flawed and a re-analysis shows that the line profile variations are indeed periodic. When combined with a 4 night timeseries taken 45 days earlier, a period near 2.27 d is found in periodograms of the Heii 5412 line centroid,rms line width, and line skew variations. When the emission line residuals are ordered as a function of phase, a sinuous feature appears to snake about the line center with an amplitude of ± 500 km s–1. This is 20 larger than the line centroid amplitude; the calculation of which is heavily weighted by static portions of the line profile. In addition to the snake, emission residuals appear that move away from line center on unbound trajectories and are thought to result from the interaction of a periodic driver with the unstable flow of the radiation driven wind. The nature of the periodic driver is a topic for discussion.  相似文献   

2.
Results of high-dispersion spectroscopy (10 Å mm–1) of the symbiotic star AX Per carried out in the years from 1979 to 1987 are reported. The emission line [FeVII] 6086 consists of a narrow and a broad component; the radial velocity of the narrow one varies according to the photometric period 681.6 days. This variation (K=30.6±1.5 km s–1) seems to be due to the orbital motion of the hot star. The radial velocity of absorption lines varies with an inverse phase dependence and a much smaller amplitude (K=5.6±2 km s–1), which may reflect the orbital motion of the red giant. The variation of the radial velocity of the emission lines of FeII, ect. (K=6.7±1.5 km s–1) might be due to the rotation of the red giant. The profile of H emission line suddenly changed around the phase of the photometric minimum, which could be explained as a result of an eclipse of the emitting region by the red giant. On the other hand, some problems remain open in the behaviour of the radial velocities of H and HeI 5876.The observed results support a binary model of AX Per consisting of a rather massive (3M ) M-type giant and a Main-Sequence star (0.6M ). AX Per seems to be in an early stage of the Case C mass transfer, and the estimated very high mass accretion rate (10–4 M yr–1) is consistent with the theoretical models. The narrow component of the emission line of [FeVII] 6086 might be emitted in radiatively driven polar jets on the hot star of which luminosity is close to the Eddington limit.A new identification as ZrII at 6106.47 Å is proposed for the emission line at 6106 Å.  相似文献   

3.
We scanned the H i L, Mg ii h and k, Ca ii K and H lines simultaneously with the LPSP instrument on OSO-8, to investigate the low and moderate temperature regions of an active region filament. The L line is not reversed except for the innermost position in the prominence. Intensity (k/h), (K/H) ratios are respectively 2 and 1.1, indicating that the Mg ii lines are optically thin, and that Ca ii K is saturated, although not clearly reversed. The results obtained during the second sequence of observations (K saturated before L for example) indicate that within the size of the slit (1 × 10) we are not observing the same emitting features in the different lines.We also observe an important line-of-sight velocity at the outer edge of the feature, increasing outwards from a few km s–1 to 20 km s–1 within 2. Less than half an hour later, this velocity is reduced to 15 km s–1 while the intensities increase. Full width at half maximum intensities for this component indicate turbulence variations from 22 to 30 km s–1. The observed high velocities at the top of the prominence can be compared with radial velocities that Mein (1977) observed in H at the edges of an active filament and interpreted as velocity loops slightly inclined on the axis of the filament.  相似文献   

4.
The physical properties in the coronal disturbance (CD) (W90, N25°) associated with an active prominence are investigated on the basis of the intensities and profiles of 5694 Å Caxv and 6702 Å Nixv lines and continuum measured in the eclipse coronal spectra of 31 July, 1981. The spectrograms have been taken with a dispersion of between 7 to 10 Å mm-1 and a solar image of 15 mm in diameter. The following characteristics of the CD have been deduced. The CD occurred cospatially with an active prominence and consisted of two discrete regions with different temperatures penetrating each other. (1) Caxv region: T e= 3.8 × 106 K, the length along the slit of the spectrograph Z 65000 km, the effective line-of-sight length L 20000 km, the average electron density , nonthermal velocities V t= (20–32) km s-1. (2)Nixv-Caxiii region: T e= 2.3 × 106 K, Z 37000 km, L 35000 km, n e 1 × 109 cm-3, V t= (23–30) km s-1. A macroscopic mass motion has been discovered within the Nixv region of the CD from the Doppler shifts of the 6702 Å Nixv line: V r= + 27 km s-1 on the lower and V r= - 12 km s-1 on the upper border of the CD. The average height of the CD was H 0.08 R . The radial velocities in the prominence found from the emission line tilts are + 12 and - 8 km s-1 on its lower and upper borders. A similar picture of the mass motion in the CD and the prominence speaks in favour of an intimate relation between them.  相似文献   

5.
Eclipsing binary TX UMa was observed with the D.A.O. high-dispersion spectrographs in 1969–1970, with emphasis on the detailed coverage of the primary minimum. One spectrum was taken exclusively within totality, thus exhibiting an uncontaminated spectrum of the secondary component. This leads to spectral reclassification of the secondary (F6 IV). The narrowing of the line profile of the H-line in totality is interpreted in terms of synchronous rotation of the secondary (v sini80 km s–1) while the primary rotates faster (v sini130 km s–1) than synchronously (v sini50 km s–1). Although the secondary does not fill in its Roche lobe fully, the system exhibits pronounced indications of rather strong physical interaction. This is now supported also by the profound changes of the line profiles of the H-line with phase.  相似文献   

6.
A one-zone model for the late time SN II energized by the radioactive decay56Ni–56Co–56Fe is presented. The model succeeds in reproducing for the late time evolution of H and [Oi] 6300 emission lines in SN1970g for the reasonable set of parameters: mass of ejecta 4M , boundary velocityv 0=4000 km s–1 and amount of56NiM Ni=0.02M . However, a one-zone model does not account for the late time continuum. In the case of SN1980k the radioactive model fits H and [Oi] 6300 emissions att250 day satisfactory but fails at very late time, e.g.,t=670 day when the predicted value of the ratioL(H)/L(6300) is two orders of magnitude smaller than the observed one. We suggest that the strong H emission in SN1980k on the 670th day is due to the interaction of the supernova envelope with the pre-SN wind. The radioactive model for the late time SN II predicts strong Mgii 2800 line and detectable Hei 10830 line in emission and absorption.  相似文献   

7.
Quiescent prominences It is found that Heii 4686 is emitted in the same cold region of 10000 K as hydrogen, metal and neutral helium emission lines. This conclusion is based on the finding that the observed width of 4686 is the same as the calculated width of 4686. The calculated width is derived from the observed widths of hydrogen and metallic lines. The large intensity of Heii 4686 in 10000 K can be explained by the ionization of Heii due to the UV radiation below 228 Å that comes from the corona and the transition region.Loop prominences The very broad width (30 to 50 km s–1) of 4686 for two post-flare loop prominences shows that the Heii line is emitted in hot regions different from regions of hydrogen and metal emission. From the widths of the Balmer lines and many metallic lines the kinetic temperature for one loop is found to be 16000 K in one part and 7600 K in another part. The electron densities are 1012.0 cm–3 and less than 1011.0 cm–3 respectively.Chromosphere The intensity of 4686 in the chromosphere can be interpreted in terms of a temperature of 10000 K with the ionization due to UV radiation. But, since observations of the width of 4686 are not available, a definitive conclusion for the chromosphere cannot be reached.  相似文献   

8.
O vi ( = 1032 Å) profiles have been measured in and above a filament at the limb, previously analyzed in H i, Mg ii, Ca ii resonance lines (Vial et al., 1979). They are compared to profiles measured at the quiet Sun center and at the quiet Sun limb.Absolute intensities are found to be about 1.55 times larger than above the quiet limb at the same height (3); at the top of the prominence (15 above the limb) one finds a maximum blue shift and a minimum line width. The inferred non-thermal velocity (29 km s–1) is about the same as in cooler lines while the approaching line-of-sight velocity (8 km s–1) is lower than in Ca ii lines.The O vi profile recorded 30 above the limb outside the filament is wider (FWHM = 0.33 Å). It can be interpreted as a coronal emission of O vi ions with a temperature of about 106 K, and a non-thermal velocity (NTV) of 49 km s–1. This NTV is twice the NTV of quiet Sun center O vi profiles. Lower NTV require higher temperatures and densities (as suggested by K-coronameter measurements). Computed emission measures for this high temperature regime agree with determinations from disk intensities of euv lines.  相似文献   

9.
An ultraviolet-excess galaxy Markarian 313 (NGC 7465), which consists of a multiple system with NGC 7463 and NGC 7464, is studied using the low- and high-resolution optical spectrum. Emission lines of H, H, [NII], and [OIII] have conspicuous blueward asymmetrical wings or blue slanted profiles in the spectrum of the nuclear region of the galaxy. The width of these emission lines is as broad as 600 km s–1 at the zero-intensity level, and the velocity difference between the narrow and broad components is estimated at around 80 km s–1 from the two-component Gaussian profile fitting. This fact could be an evidence of a large-scale dynamical motion in or surrounding the nuclear region of the galaxy, implying that it bears an intermediate characteristic between a Seyfert and a starburst galaxy.  相似文献   

10.
Two-dimensional evolutions of two flares of October 18, 1990 have been well observed in the Caii K line with a CCD camera at Norikura station of National Astronomical Observatory in Japan. There are two common characteristics for the flares: 3 - 5 min before the impulsive phase, the heating already begins at the footpoints of the flares, but no asymmetry in line emission has been detected. After the onset of the impulsive phase, Caii K line emission at the footpoints shows strong red asymmetry, with the maximum asymmetry occurring at the same time as the peak of the radio bursts. The maximum downward velocity is about 30 50 km s–1. For flare 1, blue and red asymmetries were observed in two sides of the footpoint area. They developed and attained a maximum nearly at the same time and the inferred Doppler velocities are comparable (30 40 km s–1). This implies that two mass jets started from a small region and ejected along a loop but in opposite directions with roughly equivalent momentum. A possible mechanism has been discussed.  相似文献   

11.
High dispersion time-resolved spectrograms of the dwarf nova SS Cygni, obtained with the Echelle-Mepsicron system, show double peaked emission lines with a complex profile. The intensity of the H line appears to be modulated by the orbital period. Radial velocity measurements of the wings of H and of the absorption line system of the late-type star yield semiamplitude values of Kem=101±6 km s–1 and Kab=151±7 km s–1, respectively. Radial velocity measurements of the blue and red peaks and of the central absorption of H reveal a synchronous movement with the broad wings, although there is some evidence of a narrow component probably associated with a hot spot in the disk or a chromospheric emission line from the secondary star. The H modulation, the double profile and recently discovered UBV light variations support an inclination angle i 50°. The masses of the primary are Mp=0.60 M and Ms=0.40 M, respectively. A detailed analysis of the absorption lines reveals a spectral type of K2V.Paper presented at the IAU Colloquium No. 93 Cataclysmic Variables. Recent Multi-Frequency Observations and Theoretical Developments, held at Dr. Remeis-Sternwarte Bamberg, F.R.G., 16–19 June, 1986.  相似文献   

12.
High spatial and spectral resolution observations of the ring nebula surrounding the LBV candidate He 3-519 are presented. The data were obtained at the AAT with the UCL echelle spectrograph and cover the H and [N II] emission lines for two slit positions. The nebular motions are clearly resolved and have a total velocity spread of -40 to +100 km s–1. The shell shows some deviations from spherical symmetry but overall is expanding at 61 km s–1 and has an ionized mass of 2 M. The nebular parameters are found to be similar to those of the AG Car nebula, suggesting that it resulted from a bulk ejection of material 2 × 104 yr ago.  相似文献   

13.
Bewsher  D.  Parnell  C.E.  Pike  C.D.  Harrison  R.A. 《Solar physics》2003,215(2):217-237
The relative Doppler and non-thermal velocities of quiet-Sun and active-region blinkers identified in Ov with CDS are calculated. Relative velocities for the corresponding chromospheric plasma below are also determined using the Hei line. Ov blinkers and the chromosphere directly below, have a preference to be more red-shifted than the normal transition region and chromospheric plasma. The ranges of these enhanced velocities, however, are no larger than the typical spread of Doppler velocities in these regions. The anticipated ranges of Doppler velocities of blinkers are 10–15 km s–1 in the quiet Sun (10–20 km s–1 in active regions) for Hei and 25–30 km s–1 in the quiet Sun (20–40 km s–1 in active regions) for Ov. Blinkers and the chromosphere below also have preferentially larger non-thermal velocities than the typical background chromosphere and transition region. Again the increase in magnitude of these non-thermal velocities is no greater than the typical ranges of non-thermal velocities. The ranges of non-thermal velocities of blinkers in both the quiet Sun and active regions are estimated to be 15–25 km s–1 in Hei and 30–45 km s–1 in Ov. There are more blinkers with larger Doppler and non-thermal velocities than would be expected in the whole of the chromosphere and transition region. The recently suggested mechanisms for blinkers are revisited and discussed further in light of the new results.  相似文献   

14.
We investigate the dynamics and evolution of coalescing neutron stars. The three-dimensional Newtonian equations of hydrodynamics are integrated by the Piecewise Parabolic Method on an equidistant Cartesian grid. The code is purely Newtonian, but does include the emission of gravitational waves and their back-reaction. The properties of neutron star matter are described by the equation of state of Lattimer and Swesty (1991). Energy loss by all types of neutrinos and changes of the electron fraction due to the emission of electron neutrinos and antineutrinos are taken into account by an elaborate neutrino leakage scheme. We simulate the coalescence of two identical, cool neutron stars with a baryonic mass of 1.6M and a radius of 15 km and with an initial center-to-center distance of 42 km. The initial distributions of density and electron concentration are given from a model of a cold neutron star in hydrostatic equilibrium. We investigate three cases which differ by the initial velocity distribution in the neutron stars. The orbit decays due to gravitational-wave emission and after one revolution the stars are so close that dynamical instability sets in. Within 1 ms the neutron stars merge into a rapidly spinning (P 1 ms), high-density body ( 1014 g/cm3) with a surrounding thick disk of material with densities 1010 – 1012 g/cm3 and orbital velocities of 0.3-0.5 c. The peak emission of gravitational waves has a maximum luminosity of a few times 1055 erg/s and is reached for about 1 ms. The amplitudes of the gravitational waves are close to 3 10–23 at a distance of 1 Gpc and the typical frequency is near the dynamical value of the orbital motion of the merging neutron stars of 2 KHz. In a post-processing step, the rate of neutrino-antineutrino annihilation is calculated from the neutrino luminosities generated during the hydrodynamical simulations. We find the integral annihilation rate to be a few 1050 erg/s during the phase of strongest neutrino emission, which is too small to generate the observed bursts considering the fact that the merged object of about 3M will most likely collapse to a black hole within milliseconds.  相似文献   

15.
A flare surge at the limb was observed in CIII 977 Å by the Harvard OSO 6 spectroheliometer. The kinematic behavior of the surge is the same in CIII and in H. The amount of CIII emission is consistent with a model in which the CIII ions occupy sheaths with thickness 100 km surrounding the cooler H-emitting threads. The mass of the material containing CIII ions is about 10–2 times that emitting H.Now at California Institute of Technology, Pasadena, California.  相似文献   

16.
Observations of C100 and C125 atomic carbon recombination lines were made at the Algonquin Radio Observatory, towards the neutral interface separating theHii region DR21 (at RA=20h37m14s, Dec=+42°0900) from its associated molecular cloud. An analysis of the Cn observations in conjunction with a simple model of a neutral interface enabled the derivation of the following parameters: electron density of 300 cm–3, electron temperature of 30 K, microturbulent velocity of 2.3 km s–1, and depth of the neutral interface of 0.01 pc. A single,stimulated emission model is sufficient to reproduce the Cn observations in the wavelength range from 4.6 cm (C100) to 21 cm (C166). All the known Cn data do support a pressure equilibrium between the neutral interface and theHii region, after the usual allowance is made for carbon depletion on grains.  相似文献   

17.
A technique for high-sensitivity measurements of spectral line profile fluctuations is suggested. Observations with spectral lines most commonly used to study the oscillations have been carried out. It is found that 5-min and 3-min fluctuations of Fei 5123, 5250, 5434 and NaDi 5896 line profiles are able to produce signals equivalent to line-of-sight velocities of 1–5 m s–1 at a spatial resolution of 5 and 10–35 m s–1 at 1.5 × 4 resolution. Such observations permit a better understanding of the particular physical factors responsible for the oscillations of line-of-sight velocity signals and the magnetic field which are the subject of study of helioseismology.  相似文献   

18.
During a coordinated SMY program, the consecutive formation of two new active centers merging together within AR 2646 was observed from 28 August, to 5 September, 1980. The two preceding spots compressed an inverse polarity spot on 1 September 1980, causing recurrent ejecta of matter with time intervals around 10 min. The observations of the MSDP spectrograph operating in H at the Meudon Solar tower and of the UVSP spectrometer on SMM in the Civ 1548 Å line show that cold and hot material had the same projection, although the upward Civ velocity structure was more extended than the H one. We present evidence that observed contrasts of the H absorbing structure can be interpreted in terms of a dynamic cloud model overlying the chromosphere. H matter follows a magnetic channel with upward velocity around 20–30 km s–1 in the first phase of the event and with downward velocity ( - 40 km s–1) in the second phase. The stored energy is not sufficient to trigger a flare, nor even to propulse matter along the full length of an arch, because of the periodic reorganisation of the magnetic field.  相似文献   

19.
On the basis of empirical (D)-dependency at the frequency of 5 GHz constructed using 15 planetary nebulae with the independently measured distances (10–171×10–20 W m–2 Hz–1 ster–1), we evaluated distances of 335 objects. Independent evidence of the correctness of the accepted scale are given. Then(D)-dependency is constructed and it is shown that atD<0.08 pc the mean electron density is higher than the one determined by the Seaton method. We showed that the filling factor diminishes with the increase of the PN diameter (1 atD0.08 pc and 0.2 atD0.4 pc). the ionized mass of 33 PNs is determined. With the diameter increase the ionized mass grows and atD0.4 pc reaches the valueM0.07M . We used the new distance scale when investigating the space distribution of PNs. The mean scale height =130±15 pc and the mean gradient of the change of surface densitym=0.37, which allowed us to estimate the total number of nebulae in the GalaxyN4×104. We divided the PNs according to their velocities (withV LSR>35 km s–1 andV LSR<35 km s–1) and permitted us to confirm that the PN belong to different sub-systems of the Galaxy. The estimated local formation rate of PNs [=(4.6±2.2)×10–12 pc–3 yr–1] is a little higher than the one of the white dwarfs. That can be explained by a large number of PNs having binary cores, which used in our sample. The statistical estimation of PN expansion velocity showed thatV ex increases from 5–7 km s–1 (atD0.03 pc) to 40–50 km s–1 (atD0.8 pc).  相似文献   

20.
A detailed analysis of interstellar measurements in the direction of the Gum nebula is carried out. The ionized region is shown to have an angular radius of 18° and appears to be bounded by a shell of neutral gas. The mean electron temperature deduced from radio-frequency absorption measurements is found to be 8500K. These parameters suggest that the nebula is the normal and possibly evolved Hii region of Pup and 2 Vel, rather than the fossil Strömgren sphere of the Vela supernova as suggested by Brandtet al. (1971).  相似文献   

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