Zobrazeno 1 - 10
of 104
pro vyhledávání: '"Niemelä, V."'
Autor:
Niemelä, V. (Ville)
Impulse radio ultra-wideband (IR-UWB) technology, due to its baseband signaling, potentially offers a low cost, low complexity and low power consumption option for different short range sensor network applications. These sensor networks can be applie
Externí odkaz:
http://urn.fi/urn:isbn:9789526215037
Autor:
Fernandez-Lajus, E., Farina, C., Torres, A. F., Schwartz, M. A., Salerno, N., Calderon, J. P., von Essen, C., Calcaferro, L. M., Giudici, F., Llinares, C., Niemela, V.
The periodicity of 5.5 years for some observational events occurring in Eta Carinae manifests itself across a large wavelength range and has been associated with its binary nature. These events are supposed to occur when the binary components are clo
Externí odkaz:
http://arxiv.org/abs/0812.1814
Autor:
Niemela, V. S., Gamen, R. C., Barba, R. H., Lajus, E. Fernandez, Benaglia, P., Solivella, G. R., Reig, P., Coe, M. J.
From the radial velocities of the N IV 4058 and He II 4686 emission lines, and the N V 4604-20 absorption lines, determined in digital spectra, we report the discovery that the X-ray bright emission line star Wack 2134 (= WR 21a) is a spectroscopic b
Externí odkaz:
http://arxiv.org/abs/0807.0728
context About 2500 planetary nebulae are known in our Galaxy but only 224 have central stars with reported spectral types in the Strasbourg-ESO Catalogue of Galactic Planetary Nebulae (Acker et al. 1992; Acker et al. 1996) % aims We have started an o
Externí odkaz:
http://arxiv.org/abs/0806.4968
Autor:
Damineli, A., Corcoran, M. F., Hillier, D. J., Stahl, O., Levenhagen, R. S., Leister, N. V., Groh, J. H., Teodoro, M., Colombo, J. F. Albacete, Gonzalez, F., Arias, J., Levato, H., Grosso, M., Morrell, N., Gamen, R., Wallerstein, G., Niemela, V.
Extensive spectral observations of eta Carinae over the last cycle, and particularly around the 2003.5 low excitation event, have been obtained. The variability of both narrow and broad lines, when combined with data taken from two earlier cycles, re
Externí odkaz:
http://arxiv.org/abs/0711.4250
We analyze the distribution of the interstellar matter in the environs of the HII region Gum31, excited by the open cluster NGC3324, located in the complex Carina region, with the aim of investigating the action of the massive stars on the surroundin
Externí odkaz:
http://arxiv.org/abs/0711.2458
Autor:
Apellániz, J. Maíz, Walborn, Nolan R., Morrell, N. I., Nelan, E. P., Niemela, V. S., Benaglia, P., Sota, A.
We are using HST GO programs 10205, 10602, and 10898 to test the stellar upper mass limit in the solar vicinity by attempting to detect optical close companions, thus lowering the calculated evolutionary masses. We have observed with ACS/HRC all the
Externí odkaz:
http://arxiv.org/abs/astro-ph/0702514
Is there a stellar upper mass limit? Recent statistical work seems to indicate that there is and that it is in the vicinity of 150 solar masses. In this paper we use HST and ground-based data to investigate the brightest members of the cluster Pismis
Externí odkaz:
http://arxiv.org/abs/astro-ph/0612012
Autor:
Gamen, R., Gosset, E., Morrell, N., Niemela, V., Sana, H., Naze, Y., Rauw, G., Barba, R., Solivella, G.
Publikováno v:
A&A, 460, 777-782 (2006)
Since the discovery, with the EINSTEIN satellite, of strong X-ray emission associated with HD93162 (=WR25), this object has been predicted to be a colliding-wind binary system. However, radial-velocity variations that would prove the suspected binary
Externí odkaz:
http://arxiv.org/abs/astro-ph/0609454
Autor:
Lajus, E. Fernandez, Niemela;, V. S.
Publikováno v:
Mon.Not.Roy.Astron.Soc. 367 (2006) 1709-1713
ASAS photometric observations of LS 1135, an O-type SB1 binary system with an orbital period of 2.7 days, show that the system is also eclipsing. This prompted us to re-examine the spectra used in the previously published spectroscopic orbit. Our new
Externí odkaz:
http://arxiv.org/abs/astro-ph/0601396