Radio emission from early-type galaxies and cosmic microwave background experiments     

Elena Pierpaoli †  Rosalba Perna 《Monthly notices of the Royal Astronomical Society》2004,354(4):1005-1010

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The metal abundance of circumnuclear star-forming regions in early-type spirals. Spectrophotometric observations     

Ángeles I. Díaz †  Elena Terlevich ‡  Marcelo Castellanos §  Guillermo F. Hägele ¶ 《Monthly notices of the Royal Astronomical Society》2007,382(1):251-269

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Glacier changes in the Tien Shan as determined from topographic and remotely sensed data   总被引：6，自引：1，他引：5  

Vladimir B. Aizen  Valeriy A. Kuzmichenok  Arzhan B. Surazakov  Elena M. Aizen 《Global and Planetary Change》2007,56(3-4):328

This research presents a precise evaluation of the Tien Shan glacier's recession based on data of geodetic surveys 1861–1869, aerial photographs from 1943, 1963, 1977, 1981, 1:25,000 scale topographic maps, SRTM, and ASTER data from 2000/2003 for the Akshiirak glacierized massif in the central Tien Shan with 178 glaciers covering 317.6 km², and for the Ala Archa glacier basin in the northern Tien Shan with 48 glaciers covering 36.31 km².The Tien Shan glaciers retreated as much as 3 km from the 1860s to 2003. From 1943 to 1977, Akshiirak and Ala Archa shrunk 4.2% and 5.1% respectively, and from 1977 to 2003 the area shrunk 8.6% and 10.6%, respectively. The volume of the Akshiirak glaciers was reduced by 3.566 km³ from 1943 to 1977 and 6.147 km³ from 1977 to 2000.The total reduction of the Tien Shan glacier is 14.2% during the last 60 yr. The northern and central Tien Shan have not experienced a significant increase of precipitation during the last 100 yr, but they have experienced an increase in summer air temperatures, especially observable since the 1970s, which caused an acceleration of the Tien Shan glaciers recession.  相似文献   

Evolution of the X-ray luminosity and metallicity of starburst blown superbubbles     

Sergey A. Silich  †  Guillermo Tenorio-Tagle  ‡  Roberto Terlevich  §  Elena Terlevich †¶  Hagai Netzer 《Monthly notices of the Royal Astronomical Society》2001,324(1):191-200

We have modelled the evolution of hot superbubbles in starbursts, taking into account the rapid changes in the chemical composition of the interior of the superbubbles resulting from the large stellar mass loss, i.e. stellar winds from massive young stars and type II supernovae. We have followed in detail the time-dependent production and mixing of oxygen and iron in the interior of the hot superbubbles and showed that while the oxygen abundance rapidly climbs to over solar values in less than 10 Myr, iron abundance remains always under solar. This highly enhanced oxygen metallicity boosts the early X-ray luminosity of superbubbles while keeping the iron abundance subsolar. This brings theory and X-ray observations of the luminosity and metal content of young starbursts closer together.  相似文献   

The temperature and ionization structure of the emitting gas in H ii galaxies: implications for the accuracy of abundance determinations     

Guillermo F. Hägele †  Enrique Pérez-Montero  Ángeles I. Díaz  Elena Terlevich  Roberto Terlevich ‡ 《Monthly notices of the Royal Astronomical Society》2006,372(1):293-312

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Early Norian flora from Partizansk River Basin of Primorye, Russia     

Elena B Volynets  Svetlana A Schorokhova  Ge Sun 《世界地质(英文版)》2006,9(1)

An early Norian flora from the Partizansk River Basin of Primorye, Far-East of Russia, is described in detail for the first time, in which over 25 taxa are reported. The flora is dominated by cycadoalean, bennettitalean and coniferous plants, associated with a lot of ferns and czekanowskialean plants, and with a few ginkgoalean. In floristic characteristics, the flora can be well comparable with Late Triassic Mongugai flora of southwestern Primorye and its neighboring Tianqiaoling flora of eastern Jilin, China, as well with the Yamanoi and Nariwa floras from southwestern Japan. As the plant-bearing strata are sandwiched in the lower Norian marine beds yielding marine fauna, the age of the Partizansk flora is well evidenced as the early Norian. Paleophytogeographically, the flora appears to be in the ecotone of the Medio-Triassic and Arcto-Triassic floristic regions in Eurasia, and indicates probably warm temperate or subtropic vegetation in nature. Four new species are reported in this paper, including Ctenis elegantus sp. nov, Ixostrobus pacificus sp. nov., Elatocladus elegantus sp. nov. and E. prynadae sp. nov.  相似文献   

Mv Lyr: Transition from Low to High Brightness State     

Elena Pavlenko  Kirill Antoniuk  Sergei Yu. Shugarov  Nataly A. Katysheva  Lenie Muzhdabaeva  Vyacheslav Mikhajlov 《Astrophysics and Space Science》2005,296(1-4):461-464

We present results of multicolour photometry of the nova-like binary MV Lyr in the years 2002–2003, corresponding to the transition of the star from its low (V = 17.8) to high (V = 12.3) brightness state. The transition lasted at most 200 days. During the first ∼50 days MV Lyr brightened at the rate 0.06 mag/day, and during the next ∼150 days at the rate 0.01 mag/day. The brightening was accompanied by a blue shift from 0.45 to 0.05 in V−R, interpreted as an increase of the accretion disk contribution to the total light. During the transition MV Lyr displayed well-known ‘quasi-orbital’ light variations and fast quasi-periodic oscillations with a typical time scale of tens of minutes.  相似文献   

Reconstructing Sunyaev–Zel'dovich clusters in future cosmic microwave background experiments     

Elena Pierpaoli  S. Anthoine  K. Huffenberger  I. Daubechies 《Monthly notices of the Royal Astronomical Society》2005,359(1):261-271

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Structural parameters of nearby emission-line galaxies     

Miguel Sánchez-Portal  Ángeles I. Díaz  Elena Terlevich †  Roberto Terlevich 《Monthly notices of the Royal Astronomical Society》2004,350(3):1087-1106

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Time-spectra of chromospheric activity of old solar-type stars: detection of rotational signals from double wavelet analysis     

Peter Frick  Willie Soon  Elena Popova  Sallie Baliunas   《New Astronomy》2004,9(8):599-609

We introduce a novel technique, called the double wavelet analysis (DWA), for the determination of stellar rotation periods from time serial data. This first paper aims narrowly at the discussion, introduction and application of the DWA technique to records of surface magnetism in solar-type (relatively old) lower main sequence stars that are obtained by the Mount Wilson Observatory (MWO) HK Project. The technique takes a series of careful steps that seek to optimize wavelet parameters and normalization schemes, ultimately allowing fine-tuned, arguably more accurate, estimates of rotation-modulated signals (with, e.g., periods of days to months) in records that contain longer periodicities such as stellar magnetic activity cycles (with, e.g., period of years). The apparent rotation periods estimated from the DWA technique are generally consistent with results from both “first-pass” (i.e., ordinary) global wavelet spectrum and earlier classical periodogram analyses. But there are surprises as well. For example, the rotation period of the ancient subdwarf Goombridge 1830 (HD 103095), previously identified as ≈31 days, suggests under the DWA technique a significantly slower period of 60 days. DWA spectra also generally reveal a shift in the cycle period toward high frequencies (hence shorter periods) compared to the first-pass wavelet spectrum. For solar-type stars analyzed here, the character of the DWA spectrum and slope of the first-pass global wavelet spectrum produce a classification scheme that allows a star's record to be placed into one of three categories.  相似文献