Search

Your search keyword '"Jańczak J"' showing total 48 results
Start Over Author "Jańczak J"
48 results on '"Jańczak J"'

9. Microlensing Discovery of a Population of Very Tight, Very Low-mass Binary Brown Dwarfs

Author

Choi, J. -Y., Han, C., Udalski, A., Sumi, T., Gaudi, B. S., Gould, A., Bennett, D. P., Dominik, M., Beaulieu, J. -P., Tsapras, Y., Bozza, V., Abe, F., Bond, I. A., Botzler, C. S., Chote, P., Freeman, M., Fukui, A., Furusawa, K., Itow, Y., Ling, C. H., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Ohnishi, K., Rattenbury, N. J., Saito, To., Sullivan, D. J., Suzuki, K., Sweatman, W. L., Suzuki, D., Takino, S., Tristram, P. J., Wada, K., Yock, P. C. M., Szymański, M. K., Kubiak, M., Pietrzyński, G., Soszyński, I., Skowron, J., Kozłowski, S., Poleski, R., Ulaczyk, K., Wyrzykowski, Ł., Pietrukowicz, P., Almeida, L. A., DePoy, D. L., Dong, Subo, Gorbikov, E., Jablonski, F., Henderson, C. B., Hwang, K. -H., Janczak, J., Jung, Y. -K., Kaspi, S., Lee, C. -U., Malamud, U., Maoz, D., McGregor, D., Munoz, J. A., Park, B. -G., Park, H., Pogge, R. W., Shvartzvald, Y., Shin, I. -G., Yee, J. C., Alsubai, K. A., Browne, P., Burgdorf, M. J., Novati, S. Calchi, Dodds, P., Fang, X. -S., Finet, F., Glitrup, M., Grundahl, F., Gu, S. -H., Hardis, S., Harpsøe, K., Hinse, T. C., Hornstrup, A., Hundertmark, M., Jessen-Hansen, J., Jørgensen, U. G., Kains, N., Kerins, E., Liebig, C., Lund, M. N., Lundkvist, M., Maier, G., Mancini, L., Mathiasen, M., Penny, M. T., Rahvar, S., Ricci, D., Scarpetta, G., Skottfelt, J., Snodgrass, C., Southworth, J., Surdej, J., Tregloan-Reed, J., Wambsganss, J., Wertz, O., Zimmer, F., Albrow, M. D., Bachelet, E., Batista, V., Brillant, S., Cassan, A., Cole, A. A., Coutures, C., Dieters, S., Prester, D. Dominis, Donatowicz, J., Fouqué, P., Greenhill, J., Kubas, D., Marquette, J. -B., Menzies, J. W., Sahu, K. C., Zub, M., Bramich, D. M., Horne, K., Steele, I. A., and Street, R. A.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Although many models have been proposed, the physical mechanisms responsible for the formation of low-mass brown dwarfs are poorly understood. The multiplicity properties and minimum mass of the brown-dwarf mass function provide critical empirical diagnostics of these mechanisms. We present the discovery via gravitational microlensing of two very low-mass, very tight binary systems. These binaries have directly and precisely measured total system masses of 0.025 Msun and 0.034 Msun, and projected separations of 0.31 AU and 0.19 AU, making them the lowest-mass and tightest field brown-dwarf binaries known. The discovery of a population of such binaries indicates that brown dwarf binaries can robustly form at least down to masses of ~0.02 Msun. Future microlensing surveys will measure a mass-selected sample of brown-dwarf binary systems, which can then be directly compared to similar samples of stellar binaries., Comment: 7 pages, 5 figures, 3 tables, ApJ submitted

Published
2013
Full Text
View/download PDF

11. Microlensig Binaries with Candidate Brown Dwarf Companions

Author

Shin, I. -G., Han, C., Gould, A., Udalski, A., Sumi, T., Dominik, M., Beaulieu, J. -P., Tsapras, Y., Bozza, V., Szymański, M. K., Kubiak, M., Soszyński, I., Pietrzyński, G., Poleski, R., Ulaczyk, K., Pietrukowicz, P., Kozłowski, S., Skowron, J., Wyrzykowski, Ł., Abe, F., Bennett, D. P., Bond, I. A., Botzler, C. S., Freeman, M., Fukui, A., Furusawa, K., Hayashi, F., Hearnshaw, J. B., Hosaka, S., Itow, Y., Kamiya, K., Kilmartin, P. M., Kobara, S., Korpela, A., Lin, W., Ling, C. H., Makita, S., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Nagaya, M., Nishimoto, K., Ohnishi, K., Okumura, T., Omori, K., Perrott, Y. C., Rattenbury, N., Saito, To., Skuljan, L., Sullivan, D. J., Suzuki, D., Sweatman, W. L., Tristram, P. J., Wada, K., Yock, P. C. M., Christie, G. W., Depoy, D. L., Dong, S., Gal-Yam, A., Gaudi, B. S., Hung, L. -W., Janczak, J., Kaspi, S., Maoz, D., McCormick, J., McGregor, D., Moorhouse, D., Muñoz, J. A., Natusch, T., Nelson, C., Pogge, R. W., Tan, T. -G., Polishook, D., Shvartzvald, Y., Shporer, A., Thornley, G., Malamud, U., Yee, J. C., Choi, J. -Y., Jung, Y. -K., Park, H., Lee, C. -U., Park, B. -G., Koo, J. -R., Bajek, D., Bramich, D. M., Browne, P., Horne, K., Ipatov, S., Snodgrass, C., Steele, I., Street, R., Alsubai, K. A., Burgdorf, M. J., Novati, S. Calchi, Dodds, P., Dreizler, S., Fang, X. -S., Grundahl, F., Gu, C. -H., Hardis, S., Harpsøe, K., Hinse, T. C., Hundertmark, M., Jessen-Hansen, J., Jørgensen, U. G., Kains, N., Kerins, E., Liebig, C., Lund, M., Lundkvist, M., Mancini, L., Mathiasen, M., Hornstrup, A., Penny, M. T., Proft, S., Rahvar, S., Ricci, D., Scarpetta, G., Skottfelt, J., Southworth, J., Surdej, J., Tregloan-Reed, J., Wertz, O., Zimmer, F., Albrow, M. D., Batista, V., Brillant, S., Caldwell, J. A. R., Calitz, J. J., Cassan, A., Cole, A., Cook, K. H., Corrales, E., Coutures, Ch., Dieters, S., Prester, D. Dominis, Donatowicz, J., Fouqué, P., Greenhill, J., Hill, K., Hoffman, M., Kane, S. R., Kubas, D., Marquette, J. -B., Martin, R., Meintjes, P., Menzies, J., Pollard, K. R., Sahu, K. C., Wambsganss, J., Williams, A., Vinter, C., and Zub, M.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Brown dwarfs are important objects because they may provide a missing link between stars and planets, two populations that have dramatically different formation history. In this paper, we present the candidate binaries with brown dwarf companions that are found by analyzing binary microlensing events discovered during 2004 - 2011 observation seasons. Based on the low mass ratio criterion of q < 0.2, we found 7 candidate events, including OGLE-2004-BLG-035, OGLE-2004-BLG-039, OGLE-2007-BLG-006, OGLE-2007-BLG-399/MOA-2007-BLG-334, MOA-2011-BLG-104/OGLE-2011-BLG-0172, MOA-2011-BLG-149, and MOA-201-BLG-278/OGLE-2011-BLG-012N. Among them, we are able to confirm that the companions of the lenses of MOA-2011-BLG-104/OGLE-2011-BLG-0172 and MOA-2011-BLG-149 are brown dwarfs by determining the mass of the lens based on the simultaneous measurement of the Einstein radius and the lens parallax. The measured mass of the brown dwarf companions are (0.02 +/- 0.01) M_Sun and (0.019 +/- 0.002) M_Sun for MOA-2011-BLG-104/OGLE-2011-BLG-0172 and MOA-2011-BLG-149, respectively, and both companions are orbiting low mass M dwarf host stars. More microlensing brown dwarfs are expected to be detected as the number of lensing events with well covered light curves increases with new generation searches., Comment: 10 pages, 9 figures, 4 tables

Published
2012
Full Text
View/download PDF

12. OGLE-2008-BLG-510: first automated real-time detection of a weak microlensing anomaly - brown dwarf or stellar binary?

Author

Bozza, V., Dominik, M., Rattenbury, N. J., Joergensen, U. G., Tsapras, Y., Bramich, D. M., Udalski, A., Bond, I. A., Liebig, C., Cassan, A., Fouque, P., Fukui, A., Hundertmark, M., Shin, I. -G., Lee, S. H., Choi, J. -Y., Park, S. -Y., Gould, A., Allan, A., Mao, S., Wyrzykowski, L., Street, R. A., Buckley, D., Nagayama, T., Mathiasen, M., Hinse, T. C., Novati, S. Calchi, Harpsoee, K., Mancini, L., Scarpetta, G., Anguita, T., Burgdorf, M. J., Horne, K., Hornstrup, A., Kains, N., Kerins, E., Kjaergaard, P., Masi, G., Rahvar, S., Ricci, D., Snodgrass, C., Southworth, J., Steele, I. A., Surdej, J., Thoene, C. C., Wambsganss, J., Zub, M., Albrow, M. D., Batista, V., Beaulieu, J. -P., Bennett, D. P., Caldwell, J. A. R., Cole, A, Cook, K. H., Coutures, C., Dieters, S., Prester, D. Dominis, Donatowicz, J., Greenhill, J., Kane, S. R., Kubas, D., Marquette, J. -B., Martin, R., Menzies, J., Pollard, K. R., Sahu, K. C., Williams, A., Szymanski, M. K., Kubiak, M., Pietrzynski, G., Soszynski, I., Poleski, R., Ulaczyk, K., DePoy, D. L., Dong, S., Han, C., Janczak, J., Lee, C. -U., Pogge, R. W., Abe, F., Furusawa, K., Hearnshaw, J. B., Itow, Y., Kilmartin, P. M., Korpela, A. V., Lin, W., Ling, C. H., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Ohnishi, K., Perrott, Y. C., Saito, To., Skuljan, L., Sullivan, D. J., Sumi, T., Suzuki, D., Sweatman, W. L., Tristram, P. J., Wada, K., Yock, P. C. M., Gulbis, A., Hashimoto, Y., Kniazev, A., and Vaisanen, P.

Subjects
Astrophysics - Earth and Planetary Astrophysics, Astrophysics - Solar and Stellar Astrophysics
Abstract

The microlensing event OGLE-2008-BLG-510 is characterised by an evident asymmetric shape of the peak, promptly detected by the ARTEMiS system in real time. The skewness of the light curve appears to be compatible both with binary-lens and binary-source models, including the possibility that the lens system consists of an M dwarf orbited by a brown dwarf. The detection of this microlensing anomaly and our analysis demonstrates that: 1) automated real-time detection of weak microlensing anomalies with immediate feedback is feasible, efficient, and sensitive, 2) rather common weak features intrinsically come with ambiguities that are not easily resolved from photometric light curves, 3) a modelling approach that finds all features of parameter space rather than just the `favourite model' is required, and 4) the data quality is most crucial, where systematics can be confused with real features, in particular small higher-order effects such as orbital motion signatures. It moreover becomes apparent that events with weak signatures are a silver mine for statistical studies, although not easy to exploit. Clues about the apparent paucity of both brown-dwarf companions and binary-source microlensing events might hide here., Comment: 17 pages with 8 figures, MNRAS submitted

Published
2012
Full Text
View/download PDF

13. Characterizing Lenses and Lensed Stars of High-Magnification Single-lens Gravitational Microlensing Events With Lenses Passing Over Source Stars

Author

Choi, J. -Y., Shin, I. -G., Park, S. -Y., Han, C., Gould, A., Sumi, T., Udalski, A., Beaulieu, J. -P., Street, R., Dominik, M., Allen, W., Almeida, L. A., Bos, M., Christie, G. W., Depoy, D. L., Dong, S., Drummond, J., Gal-Yam, A., Gaudi, B. S., Henderson, C. B., Hung, L. -W., Jablonski, F., Janczak, J., Lee, C. -U., Mallia, F., Maury, A., McCormick, J., McGregor, D., Monard, L. A. G., Moorhouse, D., Muñoz, J. A., Natusch, T., Nelson, C., Park, B. -G., Pogge, R. W., Tan, T. -G. "TG", Thornley, G., Yee, J. C., Abe, F., Barnard, E., Baudry, J., Bennett, D. P., Bond, I. A., Botzler, C. S., Freeman, M., Fukui, A., Furusawa, K., Hayashi, F., Hearnshaw, J. B., Hosaka, S., Itow, Y., Kamiya, K., Kilmartin, P. M., Kobara, S., Korpela, A., Lin, W., Ling, C. H., Makita, S., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Nagaya, M., Nishimoto, K., Ohnishi, K., Okumura, T., Omori, K., Perrott, Y. C., Rattenbury, N., Saito, To., Skuljan, L., Sullivan, D. J., Suzuki, D., Suzuki, K., Sweatman, W. L., Takino, S., Tristram, P. J., Wada, K., Yock, P. C. M., Szymański, M. K., Kubiak, M., Pietrzyński, G., Soszyński, I., Poleski, R., Ulaczyk, K., Wyrzykowski, Ł., Kozłowski, S., Pietrukowicz, P., Albrow, M. D., Bachelet, E., Batista, V., Bennett, C. S., Bowens-Rubin, R., Brillant, S., Cassan, A., Cole, A., Corrales, E., Coutures, Ch., Dieters, S., Prester, D. Dominis, Donatowicz, J., Fouqué, P., Greenhill, J., Kane, S. R., Menzies, J., Sahu, K. C., Wambsganss, J., Williams, A., Zub, M., Allan, A., Bramich, D. M., Browne, P., Clay, N., Fraser, S., Horne, K., Kains, N., Mottram, C., Snodgrass, C., Steele, I., Tsapras, Y., Alsubai, K. A., Bozza, V., Burgdorf, M. J., Novati, S. Calchi, Dodds, P., Dreizler, S., Finet, F., Gerner, T., Glitrup, M., Grundahl, F., Hardis, S., Harpsøe, K., Hinse, T. C., Hundertmark, M., Jørgensen, U. G., Kerins, E., Liebig, C., Maier, G., Mancini, L., Mathiasen, M., Penny, M. T., Proft, S., Rahvar, S., Ricci, D., Scarpetta, G., Schäfer, S., Schönebeck, F., Skottfelt, J., Surdej, J., Southworth, J., and Zimmer, F.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

We present the analysis of the light curves of 9 high-magnification single-lens gravitational microlensing events with lenses passing over source stars, including OGLE-2004-BLG-254, MOA-2007-BLG-176, MOA-2007-BLG-233/OGLE-2007-BLG-302, MOA-2009-BLG-174, MOA-2010-BLG-436, MOA-2011-BLG-093, MOA-2011-BLG-274, OGLE-2011-BLG-0990/MOA-2011-BLG-300, and OGLE-2011-BLG-1101/MOA-2011-BLG-325. For all events, we measure the linear limb-darkening coefficients of the surface brightness profile of source stars by measuring the deviation of the light curves near the peak affected by the finite-source effect. For 7 events, we measure the Einstein radii and the lens-source relative proper motions. Among them, 5 events are found to have Einstein radii less than 0.2 mas, making the lenses candidates of very low-mass stars or brown dwarfs. For MOA-2011-BLG-274, especially, the small Einstein radius of $\theta_{\rm E}\sim 0.08$ mas combined with the short time scale of $t_{\rm E}\sim 2.7$ days suggests the possibility that the lens is a free-floating planet. For MOA-2009-BLG-174, we measure the lens parallax and thus uniquely determine the physical parameters of the lens. We also find that the measured lens mass of $\sim 0.84\ M_\odot$ is consistent with that of a star blended with the source, suggesting that the blend is likely to be the lens. Although we find planetary signals for none of events, we provide exclusion diagrams showing the confidence levels excluding the existence of a planet as a function of the separation and mass ratio., Comment: 14 pages, 12 figures, 5 tables

Published
2011
Full Text
View/download PDF

14. Microlensing Binaries Discovered through High-Magnification Channel

Author

Shin, I. -G., Choi, J. -Y., Park, S. -Y., Han, C., Gould, A., Sumi, T., Udalski, A., Beaulieu, J. -P., Dominik, M., Allen, W., Bos, M., Christie, G. W., Depoy, D. L., Dong, S., Drummond, J., Gal-Yam, A., Gaudi, B. S., Hung, L. -W., Janczak, J., Kaspi, S., Lee, C. -U., Mallia, F., Maoz, D., Maury, A., McCormick, J., Monard, L. A. G., Moorhouse, D., Muñoz, J. A., Natusch, T., Nelson, C., Park, B. -G., Pogge, R. W., Polishook, D., Shvartzvald, Y., Shporer, A., Thornley, G., Yee, J. C., Abe, F., Bennett, D. P., Bond, I. A., Botzler, C. S., Fukui, A., Furusawa, K., Hayashi, F., Hearnshaw, J. B., Hosaka, S., Itow, Y., Kamiya, K., Kilmartin, P. M., Kobara, S., Korpela, A., Lin, W., Ling, C. H., Makita, S., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Nagaya, M., Nishimoto, K., Ohnishi, K., Okumura, T., Omori, K., Perrott, Y. C., Rattenbury, N., Saito, To., Skuljan, L., Sullivan, D. J., Suzuki, D., Sweatman, W. L., Tristram, P. J., Wada, K., Yock, P. C. M., Szymański, M. K., Kubiak, M., Pietrzyński, G., Soszyński, I., Poleski, R., Ulaczyk, K., Wyrzykowski, Ł., Kozłowski, S., Pietrukowicz, P., Albrow, M. D., Batista, V., Bramich, D. M., Brillant, S., Caldwell, J. A. R., Calitz, J. J., Cassan, A., Cole, A., Cook, K. H., Corrales, E., Coutures, Ch., Dieters, S., Prester, D. Dominis, Donatowicz, J., Fouqué, P., Greenhill, J., Hoffman, M., Jørgensen, U. G., Kane, S. R., Kubas, D., Marquette, J. -B., Martin, R., Meintjes, P., Menzies, J., Pollard, K. R., Sahu, K. C., Wambsganss, J., Williams, A., Vinter, C., Zub, M., Allan, A., Browne, P., Horne, K., Snodgrass, C., Steele, I., Street, R., Tsapras, Y., Alsubai, K. A., Bozza, V., Burgdorf, M. J., Novati, S. Calchi, Dodds, P., Dreizler, S., Finet, F., Gerner, T., Glitrup, M., Grundahl, F., Hardis, S., Harpsøe, K., Hessman, F. V., Hinse, T. C., Hundertmark, M., Kains, N., Kerins, E., Liebig, C., Maier, G., Mancini, L., Mathiasen, M., Penny, M. T., Proft, S., Rahvar, S., Ricci, D., Scarpetta, G., Schäfer, S., Schönebeck, F., Skottfelt, J., Surdej, J., Southworth, J., and Zimmer, F.

Subjects
Astrophysics - Solar and Stellar Astrophysics
Abstract

Microlensing can provide a useful tool to probe binary distributions down to low-mass limits of binary companions. In this paper, we analyze the light curves of 8 binary lensing events detected through the channel of high-magnification events during the seasons from 2007 to 2010. The perturbations, which are confined near the peak of the light curves, can be easily distinguished from the central perturbations caused by planets. However, the degeneracy between close and wide binary solutions cannot be resolved with a $3\sigma$ confidence level for 3 events, implying that the degeneracy would be an important obstacle in studying binary distributions. The dependence of the degeneracy on the lensing parameters is consistent with a theoretic prediction that the degeneracy becomes severe as the binary separation and the mass ratio deviate from the values of resonant caustics. The measured mass ratio of the event OGLE-2008-BLG-510/MOA-2008-BLG-369 is $q\sim 0.1$, making the companion of the lens a strong brown-dwarf candidate., Comment: 10 figures, 6 tables, 26 pages

Published
2011
Full Text
View/download PDF

15. A Cold Neptune-Mass Planet OGLE-2007-BLG-368Lb: Cold Neptunes Are Common

Author

Sumi, T., Bennett, D. P., Bond, I. A., Udalski, A., Batista, V., Dominik, M., Fouqué, P., Kubas, D., Gould, A., Macintosh, B., Cook, K., Dong, S., Skuljan, L., Cassan, A., Collaboration, The MOA, Abe, F., Botzler, C. S., Fukui, A., Furusawa, K., Hearnshaw, J. B., Itow, Y., Kamiya, K., Kilmartin, P. M., Korpela, A., Lin, W., Ling, C. H., Masuda, K., Matsubara, Y., Miyake, N., Muraki, Y., Nagaya, M., Nagayama, T., Ohnishi, K., Okumura, T., Perrott, Y. C., Rattenbury, N., Saito, To., Sako, T., Sullivan, D. J., Sweatman, W. L., Yock, P. C. M., Collaboration, The PLANET, Beaulieu, J. P., Cole, A., Coutures, Ch., Duran, M. F., Greenhill, J., Jablonski, F., Marboeuf, U., Martioli, E., Pedretti, E., Pejcha, O., Rojo, P., Albrow, M. D., Brillant, S., Bode, M., Bramich, D. M., Burgdorf, M. J., Caldwell, J. A. R., Calitz, H., Corrales, E., Dieters, S., Prester, D. Dominis, Donatowicz, J., Hill, K., Hoffman, M., Horne, K., J, U. G., Kains, N., Kane, S., Marquette, J. B., Martin, R., Meintjes, P., Menzies, J., Pollard, K. R., Sahu, K. C., Snodgrass, C., Steele, I., Street, R., Tsapras, Y., Wambsganss, J., Williams, A., Zub, M., Collaboration, The OGLE, Szyma, M. K., Kubiak, M., Pietrzy, G., Soszy, I., Szewczyk, O., Ulaczyk, K., Collaboration, The microFUN, Allen, W., Christie, G. W., DePoy, D. L., Gaudi, B. S., Han, C., Janczak, J., Lee, C. -U., McCormick, J., Mallia, F., Monard, B., Natusch, T., Park, B. -G., Pogge, R. W., and Santallo, R.

Subjects
Astrophysics - Earth and Planetary Astrophysics
Abstract

We present the discovery of a Neptune-mass planet OGLE-2007-BLG-368Lb with a planet-star mass ratio of q=[9.5 +/- 2.1] x 10^{-5} via gravitational microlensing. The planetary deviation was detected in real-time thanks to the high cadence of the MOA survey, real-time light curve monitoring and intensive follow-up observations. A Bayesian analysis returns the stellar mass and distance at M_l = 0.64_{-0.26}^{+0.21} M_\sun and D_l = 5.9_{-1.4}^{+0.9} kpc, respectively, so the mass and separation of the planet are M_p = 20_{-8}^{+7} M_\oplus and a = 3.3_{-0.8}^{+1.4} AU, respectively. This discovery adds another cold Neptune-mass planet to the planetary sample discovered by microlensing, which now comprise four cold Neptune/Super-Earths, five gas giant planets, and another sub-Saturn mass planet whose nature is unclear. The discovery of these ten cold exoplanets by the microlensing method implies that the mass ratio function of cold exoplanets scales as dN_{\rm pl}/d\log q \propto q^{-0.7 +/- 0.2} with a 95% confidence level upper limit of n < -0.35 (where dN_{\rm pl}/d\log q \propto q^n). As microlensing is most sensitive to planets beyond the snow-line, this implies that Neptune-mass planets are at least three times more common than Jupiters in this region at the 95% confidence level., Comment: 39 pages, 10 figures, accepted for publication in ApJ

Published
2009
Full Text
View/download PDF

16. Microlensing Event MOA-2007-BLG-400: Exhuming the Buried Signature of a Cool, Jovian-Mass Planet

Author

Dong, Subo, Bond, I. A., Gould, A., Kozlowski, Szymon, Miyake, N., Gaudi, B. S., Bennett, D. P., Abe, F., Gilmore, A. C., Fukui, A., Furusawa, K., Hearnshaw, J. B., Itow, Y., Kamiya, K., Kilmartin, P. M., Korpela, A., Lin, W., Ling, C. H., Masuda, K., Matsubara, Y., Muraki, Y., Nagaya, M., Ohnishi, K., Okumura, T., Perrott, Y. C., Rattenbury, N., Saito, To., Sako, T., Sato, S., Skuljan, L., Sullivan, D. J., Sumi, T., Sweatman, W., Tristram, P. J., Yock, P. C. M., Bolt, G., Christie, G. W., DePoy, D. L., Han, C., Janczak, J., Lee, C. -U., Mallia, F., McCormick, J., Monard, B., Maury, A., Natusch, T., Park, B. -G., Pogge, R. W., Santallo, R., Stanek, K. Z., Udalski, A., Kubiak, M., Szymanski, M. K., Pietrzynski, G., Soszynski, I., Szewczyk, O., Wyrzykowski, L., and Ulaczyk, K.

Subjects
Astrophysics
Abstract

We report the detection of the cool, Jovian-mass planet MOA-2007-BLG-400Lb. The planet was detected in a high-magnification microlensing event (with peak magnification A_max = 628) in which the primary lens transited the source, resulting in a dramatic smoothing of the peak of the event. The angular extent of the region of perturbation due to the planet is significantly smaller than the angular size of the source, and as a result the planetary signature is also smoothed out by the finite source size. Thus the deviation from a single-lens fit is broad and relatively weak (~ few percent). Nevertheless, we demonstrate that the planetary nature of the deviation can be unambiguously ascertained from the gross features of the residuals, and detailed analysis yields a fairly precise planet/star mass ratio of q = 0.0026+/-0.0004, in accord with the large significance (\Delta\chi^2=1070) of the detection. The planet/star projected separation is subject to a strong close/wide degeneracy, leading to two indistinguishable solutions that differ in separation by a factor of ~8.5. Upper limits on flux from the lens constrain its mass to be M < 0.75 M_Sun (assuming it is a main-sequence star). A Bayesian analysis that includes all available observational constraints indicates a primary in the Galactic bulge with a mass of ~0.2-0.5 M_Sun and thus a planet mass of ~ 0.5-1.3 M_Jupiter. The separation and equilibrium temperature are ~0.6-1.1AU (~5.3-9.7AU) and ~103K (~34K) for the close (wide) solution. If the primary is a main-sequence star, follow-up observations would enable the detection of its light and so a measurement of its mass and distance., Comment: 30 pages, 6 figures, Submitted to ApJ

Published
2008
Full Text
View/download PDF

46. A critical review of the novelties in the development of intravenous nanoemulsions.

Author

Czerniel J, Gostyńska A, Jańczak J, and Stawny M

Abstract

Nanoemulsions have gained increasing attention in recent years as a drug delivery system due to their ability to improve the solubility and bioavailability of poorly water-soluble drugs. This systematic review aimed to collect and critically analyze recent novelties in developing, designing, and optimizing intravenous nanoemulsions appearing in articles published between 2017 and 2022. The applied methodology involved searching two electronic databases PubMed and Scopus, using the keyword "nanoemulsion" in combination with "intravenous" or "parenteral". The resulting original articles were classified by the method of preparation into different categories. An overview of the current methods used for the preparation of such formulations, including high- and low-energy emulsification, was provided. The advantages and disadvantages of these methods were discussed, as well as their potential impact on the properties of the developed intravenous nanoemulsions. The problem of inconsistency in intravenous nanoemulsion terminology may lead to misunderstandings and misinterpretations of their properties and applications was also undertaken. Finally, the regulatory aspects of intravenous nanoemulsions, the state of the art in the field of intravenous emulsifiers, and the future perspectives were presented., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Published
2023
Full Text
View/download PDF

47. Valve-in-valve transcatheter transfemoral mitral valve implantation (ViV-TMVI): Characteristics and early results from a nationwide registry.

Author

Huczek Z, Mazurek M, Kochman J, Kralisz P, Jagielak D, Sacha J, Frank M, Targoński R, Walczak A, Rymuza B, Grodecki K, Scisło P, Jędrzejczyk S, Jańczak J, Pysz P, Rudziński PN, Demkow M, Witkowski A, Grygier M, and Wojakowski W

Abstract

Background: Valve-in-valve transcatheter transfemoral mitral valve implantation (ViV-TMVI) is an emerging treatment alternative to reoperation in high-surgical risk patients with failed mitral bioprostheses., Aim: We aimed to describe the characteristics of ViV-TMVI and evaluate its 30-day outcomes in the Polish population., Methods: A nationwide registry was initiated to collect data on all patients with failed mitral bioprosthesis undergoing ViV-TMVI in Poland. This study presents the results of a 30-day clinical and echocardiographic follow-up., Results: Overall, 27 ViV-TMVI procedures were performed in 8 centers up to May 2022 (85% from 2020 onwards). The mean (standard deviation [SD]) age was 73 (11.6) years with the median (interquartile range [IQR]) Society of Thoracic Surgeons score of 5.3% (4.3%-14.3%). Mean (SD) time between surgical implantation and ViV-TMVI was 8.2 (3.2) years. Failed Hancock II (29%) and Perimount Magna (22%) bioprostheses were most frequently treated. Mechanisms of failure were equally often pure mitral regurgitation or stenosis (both 37%) with mixed etiology in 26%. Balloon-expandable Sapien 3/Ultra valves were used in all but 1 patient. Technical success was 96.3% (1 patient required additional prosthesis). Mean (SD) transvalvular mitral gradient reached 6.7 (2.2) mm Hg and mitral valve area was 1.8 (0.4) cm2. None of the patients had moderate or severe mitral regurgitation with only 14.8% graded as mild. We achieved device success in 92.6% of patients (2 patients had mean gradient ≥10 mm Hg) and procedural success in 85.6%. There were no deaths, cerebrovascular events, or need for mitral valve surgery during the 30-day follow-up., Conclusions: In short-term follow-up, ViV-TMVI is a safe and effective alternative for patients with failed mitral bioprosthesis at high surgical risk of re-operation. Longer observations on larger samples are warranted.

Published
2023
Full Text
View/download PDF

48. The use of bioresorbable vascular scaffold Absorb BVS® in patients with stable coronary artery disease: one-year results with special focus on the hybrid bioresorbable vascular scaffolds and drug eluting stents treatment.

Author

Gil RJ, Bil J, Pawłowski T, Yuldashev N, Kołakowski L, Jańczak J, Jabłoński W, and Paliński P

Subjects
Aged, Female, Humans, Male, Middle Aged, Patient Safety, Poland, Prospective Studies, Treatment Outcome, Absorbable Implants, Coronary Artery Disease surgery, Drug-Eluting Stents, Percutaneous Coronary Intervention
Abstract

Background: The number of percutaneous coronary interventions (PCI) with bioresorbable vascular scaffolds (BVS) is in-creasing because these procedures offer additional benefits compared to PCI with classical drug eluting stents (DES) made of permanent metallic prostheses., Aim: To present the current experience of using BVS in a real life scenario in patients with stable coronary artery disease (CAD), with a special focus on the assessment of safety and effectiveness of the hybrid strategy (single stage BVS and DES implantation)., Methods: We performed a one-arm prospective registry, which enrolled patients with stable CAD in five interventional cardiology centres in Poland. All patients who met inclusion and exclusion criteria and had received at least one BVS stent during index PCI were included. The primary endpoint was the cumulative rate of major adverse cardiovascular events (MACE), consist-ing of cardiac death, myocardial infarction (MI), and clinically-driven target lesion revascularisation (TLR) at 12 months. The analysis was performed in the whole population as well as in the subgroup with the hybrid treatment (BVS + DES)., Results: Between August 2013 and April 2014 139 patients were enrolled. The mean age was 59.5 ± 5.5 years, and 34.5% of the population were women. The target vessel was located in the left anterior descending artery in most cases (65.5%). The device success rate was 100%. At 12 months, in the whole population the cumulative MACE incidence was 7.2% (n = 10), while the clinically-driven TLR rate was 5.0% (n = 7). In further analysis, in the hybrid subgroup there was no death, MI, or stent thrombosis, and only one case of clinically-driven TLR (4.5%)., Conclusions: The obtained data enable us to say that in particular clinical scenarios the simultaneous use of BVS and DES might be safe and effective.

Published
2016
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results