51 research outputs found

    X-ray observations of VY Scl type nova-like binaries in the high and low state

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    Four VY Scl-type nova-like systems were observed in X-rays during both the low and the high optical states. We examined Chandra, ROSAT, Swift and Suzaku archival observations of BZ Cam, MV Lyr, TT Ari, and V794 Aql. The X-ray flux of BZ Cam is higher during the low state, but there is no supersoft X-ray source (SSS) as hypothesized in previous articles. No SSS was detected in the low state of the any of the other systems, with the X-ray flux decreasing by a factor between 2 and 50. The best fit to the Swift X-ray spectra is obtained with a multi-component model of plasma in collisional ionization equilibrium. The high state high resolution spectra of TT Ari taken with Chandra ACIS-S and the HETG gratings show a rich emission line spectrum, with prominent lines of in Mg, Si, Ne, and S. The complexity of this spectrum seems to have origin in more than one region, or more than one single physical mechanism. While several emission lines are consistent with a cooling flow in an accretion stream, there is at least an additional component. We discuss the origin of this component, which is probably arising in a wind from the system. We also examine the possibility that the VY Scl systems may be intermediate polars, and that while the boundary layer of the accretion disk emits only in the extreme ultraviolet, part of the X-ray flux may be due to magnetically driven accretion.Comment: 13 pages, 8 figures, 7 tables. Accepted for publication by MNRA

    Constraining the Accretion Geometry of the Intermediate Polar EX Hya Using NuSTAR, Swift, and Chandra Observations

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    In magnetically accreting white dwarfs, the height above the white dwarf surface where the standing shock is formed is intimately related with the accretion rate and the white dwarf mass. However, it is difficult to measure. We obtained new data with NuSTAR and Swift that, together with archival Chandra data, allow us to constrain the height of the shock in the intermediate polar EX Hya. We conclude that the shock has to form at least at a distance of about one white dwarf radius from the surface in order to explain the weak Fe Kα 6.4 keV line, the absence of a reflection hump in the high-energy continuum, and the energy dependence of the white dwarf spin pulsed fraction. Additionally, the NuSTAR data allowed us to measure the true, uncontaminated hard X-ray (12-40 keV) flux, whose measurement was contaminated by the nearby galaxy cluster Abell 3528 in non-imaging X-ray instruments.Fil: Luna, Gerardo Juan Manuel. Consejo Nacional de Investigaciónes Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Astronomía y Física del Espacio. - Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Astronomía y Física del Espacio; ArgentinaFil: Mukai, K.. National Aeronautics and Space Administration; Estados UnidosFil: Orio, M.. Università di Padova; ItaliaFil: Zemko, P.. Università di Padova; Itali

    X-Ray Observations of VY Scl-Type Nova-Like Binaries in the High and Low State

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    Four VY Scl-type nova-like systems were observed in X-rays both during the low and the high optical states. They are BZ Cam, MV Lyr, TT Ari, and V794 Aql. Using archival ROSAT, Swift and SUZAKU observations we found that the X-ray flux for BZ Cam is higher during the low state, but there is no supersoft X-ray source (SSS) that would indicate the thermonuclear burning predicted in a previous article. The X-ray flux is lower by a factor 2–10 in the low than the high state in other systems, and does not reflect the drop in ˙M inferred from optical and UV data. The best fit model for the X-ray spectra is a collisionally ionized plasma model. The X-ray flux may originate in a shocked wind or in accretion onto polar caps in intermediate polar systems that continues even during the low state

    V4743 Sgr, a magnetic nova?

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    Two XMM Newton observations of Nova V4743 Sgr (Nova Sgr 2002) were performed shortly after it returned to quiescence, 2 and 3.5 years after the explosion. The X-ray light curves revealed a modulation with a frequency of ~0.75 mHz, indicating that V4743 Sgr is most probably an intermediate polar (IP). The X-ray spectra have characteristics in common with known IPs, with a hard thermal plasma component that can be fitted only assuming a partially covering absorber. In 2004 the X-ray spectrum had also a supersoft blackbody-like component, whose temperature was close to that of the white dwarf (WD) in the supersoft X-ray phase following the outburst, but with flux by at least two orders of magnitude lower. In quiescent IPs, a soft X-ray flux component originates at times in the polar regions irradiated by an accretion column, but the supersoft component of V4743 Sgr disappeared in 2006, indicating a possible origin different from accretion. We suggest that it may have been due to an atmospheric temperature gradient on the WD surface, or to continuing localized thermonuclear burning at the bottom of the envelope, before complete turn-off. An optical spectrum obtained with SALT 11.5 years after the outburst showed a prominent He II 4686A line and the Bowen blend, which reveal a very hot region, but with peak temperature shifted to the ultraviolet (UV) range. V4743 Sgr is the third post-outburst nova and IP candidate showing a low-luminosity supersoft component in the X-ray flux a few years after the outburst.Comment: 9 pages, 5 figures, accepted to MNRA

    Optical observations of "hot" novae returning to quiescence

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    We have monitored the return to quiescence of novae previously observed in outburst as supersoft X-ray sources, with optical photometry of the intermediate polar (IP) V4743 Sgr and candidate IP V2491 Cyg, and optical spectroscopy of these two and seven other systems. Our sample includes classical and recurrent novae, short period (few hours), intermediate period (1-2 days) and long period (symbiotic) binaries. The light curves of V4743 Sgr and V2491 Cyg present clear periodic modulations. For V4743 Sgr, the modulation occurs with the beat of the rotational and orbital periods. If the period measured for V2491 Cyg is also the beat of these two periods, the orbital one should be almost 17 hours. The recurrent nova T Pyx already shows fragmentation of the nebular shell less than 3 years after the outburst. While this nova still had strong [OIII] at this post-outburst epoch, these lines had already faded after 3 to 7 years in all the others. We did not find any difference in the ratio of equivalent widths of high ionization/excitation lines to that of the Hbeta line in novae with short and long orbital period, indicating that irradiation does not trigger high mass transfer rate from secondaries with small orbital separation. An important difference between the spectra of RS Oph and V3890 Sgr and those of many symbiotic persistent supersoft sources is the absence of forbidden coronal lines. With the X-rays turn-off, we interpret this as an indication that mass transfer in symbiotics recurrent novae is intermittent.Comment: In press in Monthly Notices of the Royal Astronomical Societ

    Protection of the right to information on one’s health – a non-jurisdictional form of protection

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    Protection of the right to information on one’s health – a non-jurisdictional form of protection / Nataliia Khodieieva, Mykola Yasynok,Yurii Kuryliuk, Stanislav Filippov, Alla Zemko, Dmytro Yasynok // International Journal of Criminology and Sociology. – 2021. – № 10. – Р. 630-635. – DOI: https://doi.org/10.6000/1929-4409.2021.10.73У статті аналізуються теоретичні аспекти захисту суб'єктивних цивільних прав та визначаються рамки цивільно-правових відносин щодо інформації про своє здоров'я. Отримано більш чіткий та повний опис особливостей реалізації права на інформацію про своє здоров'я у нормативно встановленій системі захисту суб'єктивних прав людини. Встановлено, що захист права на інформацію про своє здоров'я здійснюється вільно, і невикористання особою права на захист не є підставою для припинення цього права. Зазначається, що при захисті свого порушеного права на медичну інформацію уповноважена особа може вчиняти певні дії, не пов'язані зі зверненням до компетентних державних органів та є неюрисдикційною формою захисту. Систематизовано перелік дій фізичної особи щодо захисту права на інформацію про своє здоров'я за неюрисдикційної форми захисту зазначеного права.The article analyzes the theoretical aspects of protection as directly subjective civil rights and defines them within the framework of civil relations regarding the information on one's health. A clearer and complete description of the features of the realization of the right to information on one's health in the normatively established system of protection of subjective rights of a person has been obtained. It has been determined that the protection of the right to information on one's health is exercised freely, and the failure of a person to exercise the right to protection is not a ground for termination of this right. It is noted that during the protection of their violated right to health information, the authorized person may perform certain actions that are not related to the appeal to the competent state bodies and are a non-jurisdictional form of protection. The list of actions of an individual to protect the right to information on one’s health in the case of a non-jurisdictional form of protection of the above-mentioned right has been systematized.В статье анализируются теоретические аспекты защиты субъективных гражданских прав и определяются рамки гражданско-правовых отношений по поводу информации о своем здоровье. Получено более четкое и полное описание особенностей реализации права на информацию о своем здоровье в нормативно установленной системе защиты субъективных прав человека. Установлено, что защита права на информацию о своем здоровье осуществляется свободно, и неиспользование лицом права на защиту не является основанием для прекращения этого права. Отмечается, что при защите своего нарушенного права на медицинскую информацию уполномоченное лицо может совершать определенные действия, не связанные с обращением в компетентные государственные органы и являющиеся неюрисдикционной формой защиты. Систематизирован перечень действий физического лица по защите права на информацию о своем здоровье при неюрисдикционной форме защиты указанного права

    ОСЛОЖНЕНИЯ НА ЭТАПЕ НЕОАДЪЮВАНТНОЙ ТЕРАПИИ РАКА ГОЛОВКИ ПОДЖЕЛУДОЧНОЙ ЖЕЛЕЗЫ

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    Aim: to study complications of preoperative chemoembolization of the gastroduodenal artery and external beam radiation therapy in patients with pancreatic head cancer.Material and Methods. Sixty patients underwent chemoembolization of the gastroduodenal artery and external beam radiation therapy. Femoral artery angiography was performed using the Seldinger’s technique. Lipiodol 5–7 ml and gemcitabine 400 mg/m2 were used for transarterial chemoembolization. Radiation therapy was given at a total dose of 50 Gy (2 Gy/fraction, 5 times a week, over 5 weeks) using AGAT -R apparatus.Results. Complications after chemoembolization of the gastroduodenal artery were observed in 18.3 % of patients: abdominal pain in 3.3 % of patients; pain and nausea in 3.3 %; pain, nausea and fever in 6.7 %; pain, nausea and increased blood amylase in 1.7 %; pain, nausea and fever, blood amylase in 1.7 %; nausea, fever and blood amylase in 1.7 %. Radiation-induced injuries were observed in 23.3 % of patients: erythema in 18.3 %, grade 1 leukopenia in 1.7% and grade 2 leukopenia in 3.3 %.Conclusion. Complications of neoadjuvant therapy in terms of frequency and severity were consistent with literature data, were manageable with conservative treatment, and did not increase the duration of the preoperative period.Цель исследования – изучить частоту осложнений предоперационного этапа (химиоэмболизация желудочно-двенадцатиперстнокишечной артерии и дистанционная лучевая терапия) комбинированного лечения больных раком головки поджелудочной железы.Материал и методы. В предоперационном периоде 60 пациентам проведены химиоэмболизация желудочно-двенадцатиперстнокишечной артерии и дистанционная лучевая терапия. Для проведения ангиографии применяли чрезбедренную катетеризацию по Сельдингеру. Вводили химиоэмболизат – липиодол 5–7 мл и гемцитабин 400 мг/м2. Лучевую терапию проводили на аппарате АГАТ-Р классическим фракционированием в РОД 2 Гр 5 раз в неделю до СОД 50 Гр на протяжении 5 нед.Результаты. При выполнении химиоэмболизации желудочно-двенадцатиперстнокишечной артерии в 18,3 % случаев возникли осложнения: в 3,3 % диагностирована боль в животе, в 3,3 % – боль и тошнота, в 6,7 % – боль, тошнота и повышение температуры тела, в 1,7 % – боль, тошнота и повышение амилазы крови, в 1,7 % – боль, тошнота и повышение температуры тела, амилазы крови, в 1,7 % – тошнота, повышение температуры тела и амилазы крови. При проведении дистанционной лучевой терапии в 23,3 % возникли лучевые повреждения: эритема I степени – в 18,3 % случаев, лейкопения I степени – в 1,7 %, лейкопения II степени – в 3,3 % наблюдений.Заключение. Осложнения неоадъювантной терапии больных раком головки поджелудочной железы по частоте и тяжести соответствуют литературным данным, купируются консервативными мероприятиями, не увеличивая продолжительности предоперационного периода комбинированного лечения

    Multiwavelength observations of V407 Lupi (ASASSN-16kt) --- a very fast nova erupting in an intermediate polar

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    We present a detailed study of the 2016 eruption of nova V407 Lupi (ASASSN-16kt), including optical, near-infrared, X-ray, and ultraviolet data from SALT, SMARTS, SOAR, Chandra, Swift, and XMM-Newton. Timing analysis of the multiwavelength light-curves shows that, from 168 days post-eruption and for the duration of the X-ray supersoft source phase, two periods at 565 s and 3.57 h are detected. We suggest that these are the rotational period of the white dwarf and the orbital period of the binary, respectively, and that the system is likely to be an intermediate polar. The optical light-curve decline was very fast (t2t_2 \leq 2.9 d), suggesting that the white dwarf is likely massive (1.25\gtrsim 1.25 M_{\odot}). The optical spectra obtained during the X-ray supersoft source phase exhibit narrow, complex, and moving emission lines of He II, also characteristics of magnetic cataclysmic variables. The optical and X-ray data show evidence for accretion resumption while the X-ray supersoft source is still on, possibly extending its duration

    SMSS J130522.47-293113.0: A high-latitude stellar X-ray source with pc-scale outflow relics?

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    We report the discovery of an unusual stellar system SMSS J130522.47-293113.0. The optical spectrum is dominated by a blue continuum together with emission lines of hydrogen, neutral, and ionized helium, and the NIII, CIII blend at ~4640-4650 Å. The emission-line profiles vary in strength and position on time-scales as short as 1 d, while optical photometry reveals fluctuations of as much as ~0.2mag in g on time-scales as short as 10-15 min. The system is a weak X-ray source (f 0.3-10 = (1.2 ± 0.1) × 10 -13 ergs cm 2 s -1 in the 0.3-10 keV band) but is not detected at radio wavelengths (3s upper limit of 50 µJy at 5.5 GHz). The most intriguing property of the system, however, is the existence of two 'blobs', a few arcsec in size, that are symmetrically located 3'. 8 (2.2 pc for our preferred system distance of ~2 kpc) each side of the central object. The blobs are detected in optical and near-IR broad-band images but do not show any excess emission in Ha images. We discuss the interpretation of the system, suggesting that the central object is most likely a nova-like CV, and that the blobs are relics of a pc-scale accretion-powered collimated outflow
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