405 research outputs found
OGLE-2013-BLG-0911Lb: A Secondary on the Brown-dwarf Planet Boundary around an M Dwarf
We present the analysis of the binary-lens microlensing event OGLE-2013-BLG-0911. The best-fit solutions indicate the binary mass ratio of q 0.03, which differs from that reported in Shvartzvald et al. The event suffers from the well-known close/wide degeneracy, resulting in two groups of solutions for the projected separation normalized by the Einstein radius of s ~ 0.15 or s ~ 7. The finite source and the parallax observations allow us to measure the lens physical parameters. The lens system is an M dwarf orbited by a massive Jupiter companion at very close (M_(host) = 0.30^(+0.08)_(-0.06)M⊙, M_(comp) = 10.1^(+2.9)_(-2.2)M_(Jup), a_(exp) = 0.40^(+0.05)_(-0.04) au) or wide (M_(host) = 0.28^(+0.10)_(-0.08) M⊙, M_(comp) = 9.9^(+3.8)_(-3.5)M_(Jup), a(exp) = 18.0^(+3.8)_(3.5) au) separation. Although the mass ratio is slightly above the planet-brown dwarf (BD) mass-ratio boundary of q = 0.03, which is generally used, the median physical mass of the companion is slightly below the planet-BD mass boundary of 13M_(Jup). It is likely that the formation mechanisms for BDs and planets are different and the objects near the boundaries could have been formed by either mechanism. It is important to probe the distribution of such companions with masses of ~13M_(Jup) in order to statistically constrain the formation theories for both BDs and massive planets. In particular, the microlensing method is able to probe the distribution around low-mass M dwarfs and even BDs, which is challenging for other exoplanet detection methods
30P Nowa fizyczna metoda wczesnego diagnozowania i monitorowania leczenia chorych z rozpoznaniem nowotworu
Pole magnetyczne o indukcji B > 10 tesli znajduje zastosowanie w analizie indukowanej dwójłomności kołowej surowicy krwi. Analiza oddziaływania silnego pola magnetycznego i elektromagnetycznego pola wiązki świetlnej z surowicą krwi wykazała, że w silnym polu magnetycznym ujawnia się wyraźnie ilościowa różnica magneto-optycznych efektów obserwowanych dla surowic dawców krwi chorych z nowotworami. Dokonano analizy 110 surowic krwi. Pomiary wykonano w silnym impulsowym (B ≅ 30 tesli). Próbki surowicy 23 dawców krwi zostały poddane badaniom mającym na celu określenie naturalnej aktywności optycznej. Surowice te stanowiły punkt odniesienia do analiz surowic chorych onkologicznych. Analizowano surowice chorych z rozpoznaniem raka prostaty, jelita grubego, raka jajnika, w którym w trakcie leczenia oznacza się poziom markerów nowotworowych. Druga grupa chorych to pacjenci z mierzalnymi guzami gruczołu piersiowego, mięsaka, czerniaka, szpiczaka. Dokonano pomiarów magneto-optycznych współczynników a, b, c oraz naturalnej aktywności optycznej α0 surowic.Wykazano wyraźną współzależność między stanem chorego, a wartością współczynnika b oraz jego korelacją ze wzrostem poziomu markerów nowotworowych lub wielkością ognisk przerzutowych. Prowadzone po raz pierwszy badania magnatyczno-optycznej dwójłomności kołowej surowicy są szybką metodą analityczną. Mogą w przyszłości mieć zastosowanie w diagnostyce i monitorowaniu leczenia nowotworów
Production of magnesium-aluminium bimetallic bars using the explosive cladding method
The paper presents the results of the preparation of semi-finished products in the form of magnesium-aluminium round bimetallic bars by the explosive cladding method. The system of samples consisted of an aluminium tube (1050 grade) and magnesium bar (grade AZ31) was prepared. The analysis of microstructure and mechanical tests of the joint quality was carried out. On the base of obtained results it was found that the explosive cladding parameters used to obtain the semi-finished bimetallic product characterized by a slight ovality and mechanical connection of the individual layers were correct
OGLE-2013-BLG-0911Lb: A Secondary on the Brown-dwarf Planet Boundary around an M Dwarf
We present the analysis of the binary-lens microlensing event OGLE-2013-BLG-0911. The best-fit solutions indicate the binary mass ratio of q 0.03, which differs from that reported in Shvartzvald et al. The event suffers from the well-known close/wide degeneracy, resulting in two groups of solutions for the projected separation normalized by the Einstein radius of s ~ 0.15 or s ~ 7. The finite source and the parallax observations allow us to measure the lens physical parameters. The lens system is an M dwarf orbited by a massive Jupiter companion at very close (M_(host) = 0.30^(+0.08)_(-0.06)M⊙, M_(comp) = 10.1^(+2.9)_(-2.2)M_(Jup), a_(exp) = 0.40^(+0.05)_(-0.04) au) or wide (M_(host) = 0.28^(+0.10)_(-0.08) M⊙, M_(comp) = 9.9^(+3.8)_(-3.5)M_(Jup), a(exp) = 18.0^(+3.8)_(3.5) au) separation. Although the mass ratio is slightly above the planet-brown dwarf (BD) mass-ratio boundary of q = 0.03, which is generally used, the median physical mass of the companion is slightly below the planet-BD mass boundary of 13M_(Jup). It is likely that the formation mechanisms for BDs and planets are different and the objects near the boundaries could have been formed by either mechanism. It is important to probe the distribution of such companions with masses of ~13M_(Jup) in order to statistically constrain the formation theories for both BDs and massive planets. In particular, the microlensing method is able to probe the distribution around low-mass M dwarfs and even BDs, which is challenging for other exoplanet detection methods
First Space-based Microlens Parallax Measurement of an Isolated Star: Spitzer Observations of OGLE-2014-BLG-0939
We present the first space-based microlens parallax measurement of an
isolated star. From the striking differences in the lightcurve as seen from
Earth and from Spitzer (~1 AU to the West), we infer a projected velocity
v_helio,projected ~ 250 km/s, which strongly favors a lens in the Galactic Disk
with mass M=0.23 +- 0.07 M_sun and distance D_L=3.1 +- 0.4 kpc. An ensemble of
such measurements drawn from our ongoing program could be used to measure the
single-lens mass function including dark objects, and also is necessary for
measuring the Galactic distribution of planets since the ensemble reflects the
underlying Galactic distribution of microlenses. We study the application of
the many ideas to break the four-fold degeneracy first predicted by Refsdal 50
years ago. We find that this degeneracy is clearly broken, but by two
unanticipated mechanisms.Comment: 26 pages, 3 figures, submitted to Ap
Spitzer as Microlens Parallax Satellite: Mass Measurement for the OGLE-2014-BLG-0124L Planet and its Host Star
We combine Spitzer and ground-based observations to measure the microlens
parallax vector , and so the mass and distance of
OGLE-2014-BLG-0124L, making it the first microlensing planetary system with a
space-based parallax measurement. The planet and star have masses and and are separated by AU in projection. The main source of uncertainty in all these numbers
(approximately 30%, 30%, and 20%) is the relatively poor measurement of the
Einstein radius , rather than uncertainty in ,
which is measured with 2.5% precision. This compares to 22% based on OGLE data
alone, implying that the Spitzer data provide not only a substantial
improvement in the precision of the measurement but also the
first independent test of a ground-based measurement.Comment: submitted to ApJ, 30 pages, 6 figures, 4 table
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