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Using the bulge data from AGN image decomposition with ground-based observations, we calculate the ratios of the central supermassive black hole mass(SMBH) to the Bulge mass (Mbh/MbulgeMbh/Mbulge) in a sample of X-ray selected AGNs, including 15 Narrow-line Seyfert 1 galaxies (NLS1s) and 18 broad-line Seyfert 1 galaxies (BLS1s). We found that the mean value of log(Mbh/Mbulge)log(Mbh/Mbulge) is -3.81±0.11-3.81±0.11 for 15 NLS1s, and -2.91±0.13-2.91±0.13 for 18 BLS1s, showing the lower Mbh/MbulgeMbh/Mbulge in NLS1s relative to BLS1s. The calculation shows that the Bulge mass from the host image decomposition in NLS1s is statistically smaller than that from Hubble-type correction method, and a linear mass relation is suggested for NLS1s and a nonlinear mass relation for BLS1s. The studying of host galaxies with ground-based observations strongly limited by the atmospheric seeing. We need to do the decomposition of host images for NLS1s with Hubble Space Telescope observation in the future.  相似文献   

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We present medium resolution near-infrared host galaxy spectra of low redshift quasars, PG 0844+3490844+349 (z = 0.064), PG 1226+0231226+023 (z = 0.158), and PG 1426+0151426+015 (z = 0.086). The observations were done by using the Infrared Camera and Spectrograph (IRCS) at the Subaru 8.2 m telescope. The full width at half maximum of the point spread function was about 0.3 arcsec by operations of an adaptive optics system, which can effectively resolve the quasar spectra from the host galaxy spectra. We spent up to several hours per target and developed data reduction methods to reduce the systematic noises of the telluric emissions and absorptions. From the obtained spectra, we identified absorption features of Mg I (1.503 μm), Si I (1.589 μm) and CO (6-3) (1.619 μm), and measured the velocity dispersions of PG 0844+3490844+349 to be 132 ± 110 km s−1 and PG 1426+0151426+015 to be 264 ± 215 km s−1. By using an MBH–σMBHσ relation of elliptical galaxies, we derived the black hole (BH) mass of PG 0844+3490844+349, log(MBH/M)=7.7±5.5log(MBH/M)=7.7±5.5 and PG 1426+015,log(MBH/M)=9.0±7.51426+015,log(MBH/M)=9.0±7.5. These values are consistent with the BH mass values from broad emission lines with an assumption of a virial factor of 5.5.  相似文献   

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The visible and near infrared channels, Ch1 and CH2 respectively, on the Advanced Very High Resolution Radiometer (AVHRR) provide daily information for monitoring changes in vegetation and crops. Data from these channels are used to create a normalized vegetation index (NVI) that is sensitive to changes in green leaf biomass and is represented mathematically by:
NVI = CH2 ? CH1CH2 + CH1
Operational products generated at NOAA include full-scale 1-km resolution images of the NVI covering areas viewed in a single swath of the polar-orbiting NOAA satellite. Global scale NVI images are also produced by compositing over a seven-day period, saving the maximum NVI created daily for each local array (resolution of 15 km at the equator to 30 km at the poles). Such seven-day mapping reduces the effect of cloud contamination. The global vegetation indices are used by foreign and U.S. government agencies for operational and experimental purposes such as assessment of crop conditions, monitoring potential desert locust breeding grounds, forest fire danger models, and monitoring range lands for forage availability. Examples include changes in the NVI in the Lake Chad vicinity, 1981–1982 and 1984; western United States NVI; and seasonal variations of the NVI in the Sahel using the global operational data base, 1982–1983.  相似文献   

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Doppler and ranging measurements using the radio signal of the GIOTTO spacecraft were taken before, during, and after the encounter with Comet Halley on 1314 March 1986. The spacecraft velocity was found to decrease by a total of 23.3 cm s?1 due to impacting gas and (primarily) dust in the cometary atmosphere. A preliminary dust production rate Qd ? 10 × 103kg s?1 is found to be consistent with this deceleration. Power spectra of the carrier phase fluctuations reveal an increase in level and a flattening of the spectrum just prior to encounter, presumably associated with the enhanced dust impact rate. Finally, simulated Doppler time profiles are computed using the radial dependence of plasma density observed by the GIOTTO in situ investigations. It is shown that the cometary electron content profile would have been clearly seen if a dual-frequency downlink radio configuration had been available at encounter.  相似文献   

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Very Large Array (V.L.A.) measurements at 20 cm wavelength map emission from coronal loops with second-of-arc angular resolution at time intervals as short as 3.3 seconds. The total intensity of the 20 cm emission describes the evolution and structure of the hot plasma that is detected by satellite X-ray observations of coronal loops. The circular polarization of the 20 cm emission describes the evolution, strength and structure of the coronal magnetic field. Preburst heating and magnetic changes that precede burst emission on time scales of between 1 and 30 minutes are discussed. Simultaneous 20 cm and soft X-ray observations indicate an electron temperature Te 2.5 × 107 K and electron density Ne 1010 cm?3 during preburst heating in a coronal loop that was also associated with twisting of the entire loop in space. We also discuss the successive triggering of bursts from adjacent coronal loops; highly polarized emission from the legs of loops with large intensity changes over a 32 MHz change in observing frequency; and apparent motions of hot plasma within coronal loops at velocities V > 2,000 kilometerspersecond.  相似文献   

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We note that far-from-equilibrium chemical systems can respond very sensitively to gravity. The response could be in selection of possible structures or in the formation of propagating bands. In these cases the sensitivity is characterized by the factor (Eg/kT)1n, where n=2 or 3, Eg the interaction energy, k the Boltzmann constant and T, the temperature. Also, taking the thermodynamic fluctuations into account, we obtain the theoretical limit for the minimum field strength measurable by such systems.  相似文献   

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Power-law spectra f(E)∝E?2.7 of < 40 keV suprathermal ions within ~107 km of propagating interplanetary shocks are explained by diffusive scattering near a plane shock. The theory fits the 25 November 1977 event with a mean free path perpendicular to the shock with is 0.01 AU in front of the shock and less than .0003 AU behind it, for 1 keV ions. The theory predicts a steepening spectrum at higher energies, of the form f(v)∝v?4exp(??λdv/ur) where u = (ΔV)2/2VW depends on the plasma velocity jump ΔV and the plasma speed VW and mean free path λ in front of the shock  相似文献   

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Amino and hydroxy acids have been identified in the Murchison meteorite. Their presence is consistent with a synthetic pathway involving aldehydes, hydrogen cyanide and ammonia in an aqueous environment (Strecker-cyanohydrin synthesis). From the various equilibrium and rate constants involved in this synthesis, four independent estimates of the ammonium ion concentrations on the parent body at the time of compound synthesis are obtained; all values are about 2 × 10?3 M. Succinic acid and β-alanine have also been detected in the Murchison meteorite. Their presence is consistent with a synthesis from acrylonitrile, hydrogen cyanide and ammonia. Using the equilibrium and rate constants for this synthetic pathway, and the succinic acid/β-alanine ratio measured in the Murchison meteorite, an estimate of the hydrogen cyanide concentration of 10?3 to 10?2 M is obtained. Since hydrogen cyanide hydrolyzes relatively rapidly in an aqueous environment (t12 < 104yrs) this high concentration implies a period of synthesis of organic compounds as short as 104 years on the Murchison meteorite parent body.  相似文献   

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GIRL is a liquid helium cooled 50 cm telescope equipped with four focal plane instruments dedicated to astronomical and aeronomical observations. These instruments, a detector array, a photopolarimeter, an Ebert-Fastie-spectrometer and a Michelson-interferometer make up an “infrared observatory” having high sensitivity and high spectral and spatial resolution. Si:Ga-, Si:Sb-, Si:As-, Si:P-, Ge:Be-, Ge:Cu- and Ge:Ga-detectors with NEP-values as low as 3 10?17 W Hz?12 have been tested and will be used to cover the wavelength range 3…120 μm. A full size “thermal model” of the GIRL cryostat containing 300 1 of superfluid helium at 1.6 K has been tested at the industrial prime contractor MBB; results of these tests will be presented in a following paper by F. Dahl et al. Several new techniques for cold telescopes are used in GIRL, for instance a glass ceramics primary mirror, a low power chopping secondary and an active helium phase separator. The scientific objectives include studies of star formation regions and active galaxies as well as measurements of spurious gases in the earth atmosphere. GIRL will be pointed by the Instrument Pointing System (IPS) and is scheduled to fly on Spacelab in 1986/87.  相似文献   

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