Tidal disruption of a super-Jupiter by a massive black hole

Aims: A strong, hard X-ray flare was discovered (IGR J12580+0134) by INTEGRAL in 2011, and is associated to NGC 4845, a Seyfert 2 galaxy never detected at high-energy previously. To understand what happened we observed this event in the X-ray band on several occasions. Methods: Follow-up observations with XMM-Newton, Swift, and MAXI are presented together with the INTEGRAL data. Long and short term variability are analysed and the event wide band spectral shape modelled. Results: The spectrum of the source can be described with an absorbed (N_H ~ 7x10^22 cm^{-2}) power law (\Gamma \simeq 2.2), characteristic of an accreting source, plus a soft X-ray excess, likely to be of diffuse nature. The hard X-ray flux increased to maximum in a few weeks and decreased over a year, with the evolution expected for a tidal disruption event. The fast variations observed near the flare maximum allowed us to estimate the mass of the central black hole in NGC 4845 as ~ 3x10^5 Msun. The observed flare corresponds to the disruption of about 10% of an object with a mass of 14-30 Jupiter. The hard X-ray emission should come from a corona forming around the accretion flow close to the black hole. This is the first tidal event where such a corona has been observed.Comment: 8 pages, 10 figures, 4 table

Interleukin-6 and its considerable role in the pathogenesis of thyrotoxicosis-related disturbances of bone turnover in postmenopausal women

Background: Thyrotoxicosis is more frequent in postmenopausal women than in the general population, effectively accelerating bone turnover. Interleukin-6 has been shown to be involved in the pathogenesis of bone disorders. Thus, the aim of the present study was to assess the role of IL-6 and its soluble receptor in the pathogenesis of thyrotoxicosis-related disturbances of bone turnover in oestrogen-deficient women. Material and methods: The study was carried out in 40 subjects with toxic nodular goitre in three groups: Group 1 &#8212; 13 premenopausal females, mean age 36 &#177; 15 years (PremTx&#8594;PremEu); Group 2 &#8212; 12 postmenopausal females, mean age 66 &#177; 14 years (PostTx&#8594;PostEu); and Group 3 &#8212; 15 males, mean age 45 &#177; 21 years (MTx&#8594;MEu). Overt thyrotoxicosis and euthyreosis after treatment with thyrostatics were confirmed by thyrotropin, free thyroxine and free triiodothyronin concentrations. Serum levels of bone turnover markers: TRACP5b and osteocalcin as well as serum IL-6 and IL-6sR were determined using ELISA kits. Results: TRACP5b/osteocalcin quotient was significantly elevated in the PostTx females compared to the PremTx women (p < 0.02). There was a positive correlation between serum TRACP5b and osteocalcin in the studied patients (R = 0.45, p < 0.001). Levels of serum IL-6 values were significantly elevated in PostTx: 3.0 (2.14&#8211;6.40) and MTx: 2.24 (1.60&#8211;5.10), compared to PremTx females: 1.39 (0.96&#8211;2.14) (p < 0.01 and p < 0.05 respectively). There were significant positive correlations between IL-6 and IL-6sR concentrations (R = 0.22, p < 0.05) and between IL-6sR and TRACP5b serum levels (R = 0.23, p < 0.05). Conclusions: The results of our study suggest that interleukin-6 plays a considerable role in the pathogenesis of thyrotoxicosis-related disturbances of bone turnover in oestrogen-deficient women. (Pol J Endocrinol 2011; 62 (4): 299&#8211;302)Wstęp: Nadczynność tarczycy występuje częściej u kobiet po menopauzie w porównaniu z populacją ogólną, skutecznie przyspieszając obrót kostny. Wykazano, że interleukina 6 (IL-6) odgrywa istotną rolę w regulacji obrotu kostnego. Uwzględniając ten fakt, celem obecnej pracy była próba oceny roli IL-6 i jej rozpuszczalnego receptora w patogenezie zaburzeń obrotu kostnego w przebiegu tyreotoksykozy u kobiet po menopauzie. Materiał i metody: Badanie przeprowadzono u 40 osób z nadczynnym wolem guzkowym w 3 grupach: 1 &#8212; 13 kobiet przed menopauzą w wieku 36 &#177; 15 lat (PremTx&#198;PremEu), 2 &#8212; 12 kobiet po menopauzie w wieku 66 &#177; 14 lat (PostTx&#198;PostEu) i 3 &#8212; 15 mężczyzn w wieku 45 &#177; 21 lat (MTx&#198;MEu). Stan czynnościowy tarczycy potwierdzono oznaczeniem TSH, fT3 i fT4 w surowicy. Markery obrotu kostnego: TRACP5b i osteokalcyna oraz IL-6 i IL-6sR w surowicy, oznaczono zestawami ELISA. Wyniki: Iloraz TRACP5b/osteokalcyna był istotnie zwiększony u kobiet PostTx w porównaniu z grupą PremTx (p < 0,02). Stwierdzono dodatnią korelację między TRACP5b i osteokalcyną (R = 0,45, p < 0,001). Stężenie IL-6 było istotnie zwiększone w grupie PostTx: 3,0 (2,14&#8211;6,40) i MTx: 2,24 (1,60&#8211;5,10) w porównaniu z odnotowanym u kobiet z grupy PremTx: 1,39 (0,96&#8211;2,14) (odpowiednio: p < 0,01 i p < 0,05). Wykazano istotną dodatnią korelację pomiędzy IL-6 i IL-6sR (R = 0,22, p < 0,05) oraz pomiędzy IL-6sR i TRACP5b (R = 0,23, p < 0,05). Wnioski: Podsumowując, wyniki obecnej pracy wskazują, że IL-6 odgrywa ważną rolę w patogenezie zaburzeń obrotu kostnego w przebiegu tyreotoksykozy u kobiet po menopauzie. (Endokrynol Pol 2011; 62 (4): 299&#8211;302

Deep absorption in SDSS J110511.15+530806.5

We study the origin of the anomalous deep absorption in a spectrum of the SDSS J110511.15+530806.5 distant quasar (z=1.929) obtained by the Sloan Digital Sky Survey in Data Release 7 of the optical catalog. We aim to estimate the velocity of absorbing material, and we show that this material considerably affects our measurements of the black hole (BH) mass in massive quasars with the use of common virial mass estimators. The spectral shape of the quasar was modeled assuming that the accretion disk emission is influenced by a hot corona, warm skin, and absorbing material located close to the nucleus. The whole analysis was undertaken with XSPEC models and tools. The overall spectral shape was represented with the AGNSED model, while the deep absorption is well described by two Gaussians. The observed spectrum and the fitting procedure allowed us to estimate the BH mass in the quasar as $3.52 \pm 0.01 \times 10^9 M_{\odot}$, the nonzero BH spin is $a_* = 0.32 \pm 0.04$, and the accretion rate is $\dot m=0.274 \pm 0.001$. The velocities of the detected absorbers lie in the range of 6330-108135 km/s. When we consider that absorption is caused by the CIV ion, one absorber is folding toward the nucleus with a velocity of 73887 km/s. We derived a BI index of about 20300 km/s and a mass outflow rate up to 38.5 % of the source accretion rate. The high absorption observed in SDSS J110511.15+530806.5 is evidence of fast winds that place the source in the group of objects on the border with UFO (ultra-fast outflows), strong broad absorption line (BAL), and fast failed radiatively accelerated dusty outflow (FRADO). This absorption affects the BH mass measurement by two orders of magnitude as compared to virial mass estimation.Comment: Accepted for publication in Astronomy & Astrophysics (A&A). 10 pages, 7 figure

An X-ray Bright Nucleus in the Low Surface Brightness Galaxy UGC 6614

We report a study of the X-ray emission from the nuclear region of the low surface brightness (LSB) galaxy UGC 6614. Very little is known about the central objects in LSB galaxies especially their X-ray properties and X-ray spectra. In this study we have used XMM-Newton archival data to study the characteristics of the X-ray spectrum and the X-ray flux variability of the AGN in the LSB galaxy UGC 6614. The nucleus of UGC 6614 is very bright in X-ray emission with an absorption corrected 0.2-10.0 keV luminosity of ~1.1 x 10^{42} erg s^{-1}. The X-ray spectrum is found to be power-law type with a moderate column density. A short time scale of intensity variation and large X-ray flux is indicative of the presence of a black hole at the centre of this galaxy. Using the method of excess variance, we have determined the black hole mass to be ~0.12 x 10^{6} solar mass. The X-ray spectral properties are similar to that of the Seyfert I type AGNs. Our study thus demonstrates that although LSB galaxies are poor in star formation, they may harbour AGNs with X-ray properties comparable to that seen in more luminous spiral galaxies.Comment: 5 pages, 4 figures, Accepted for publication in MNRA

Black hole masses from power density spectra: determinations and consequences

We analyze the scaling of the X-ray power density spectra with the mass of the black hole on the example of Cyg X-1 and Seyfert 1 galaxy NGC 5548. We show that the high frequency tail of the power density spectrum can be successfully used for determination of the black hole mass. We determine the masses of the black holes in 6 Broad Line Seyfert 1 galaxies, 5 Narrow Line Seyfert 1 galaxies and two QSOs using available power density spectra. The proposed scaling is clearly appropriate for other Seyfert galaxies and QSOs. In all but 1 normal Seyferts the resulting luminosity to the Eddington luminosity ratio is smaller than 0.15, with a source MCG -6-15-30 being an exception. The applicability of the same scaling to Narrow Line Seyfert 1 is less clear and there may be a systematic shift between the power spectra of NLS1 and S1 galaxies of the same mass, leading to underestimation of the black hole mass. However, both the method based on variability and the method based on spectral fitting show that those galaxies have relatively low masses and high luminosity to the Eddington luminosity ratio, supporting the view of those objects as analogs of galactic sources in their high/soft or very high state based on the overall spectral shape. Bulge masses of their host galaxies are similar to normal Seyfert galaxies so they do not follow the black hole mass-bulge mass relation for Seyfert galaxies, being evolutionary less advanced, as suggested by Mathur (2000). The bulge mass-black hole mass relation in our sample is consistent with being linear, with black hole to bulge ratio $\sim$ 0.03 %, similar to Wandel (1999) and Laor (1998, 2001) for low mass objects but significantly shifted from the relation of Magorrian et al. (1998) and McLure & Dunlop (2000).Comment: 11 pages, 7 figures, 1 table, accepted for publication in MNRA

Serum interleukin-16 and RANTES during treatment of Graves&prime; orbitopathy with corticosteroids and teleradiotherapy

Introduction: To assess the usefulness of circulating IL-16 and RANTES measurements as markers of Graves&prime; orbitopathy (GO) activity and to estimate the role of these cytokines in GO pathogenesis. Material and methods: 42 individuals were divided into four groups: Group 1 comprised 15 euthyroid patients with clinical symptoms of GO who underwent corticosteroid therapy consisting of intravenous infusions of methylprednisolone (MP) and teleradiotherapy (TR); Group 2 comprised ten patients with hyperthyroid GD (Gtx); Group 3 comprised ten patients with GD in euthyreosis (Geu); and Group 4 comprised seven healthy volunteers age- and sex-matched to Groups 1&#8211;3. Serum samples were collected 24 hours before the first dose of MP, 24 hours after the first dose of MP, before TR, and at the end of therapy. Serum IL-16 and RANTES were determined by ELISA and TSH-Rab by RIA. Results: Serum IL-16 levels in patients with GO were significantly elevated at the end of therapy: 346 pg/mL (257&#8211;538) compared to IL-16 values before treatment: 250 ng/mL (211&#8211;337) and to the control group. RANTES serum concentrations did not significantly differ between studied groups, and immunosuppressive treatment did not influence its level. A negative correlation between TSH-Rab and RANTES was found in all studied groups (R = &#8211;0.32, p < 0.01). Conclusions: Our data suggests that IL-16 may exert an immunoregulatory effect in Graves&prime; orbitopathy. Serum measurements of both IL-16 and RANTES may be clinically useful; however, establishing their place in the diagnostics and treatment monitoring of GO needs further research. (Pol J Endocrinol 2012; 63 (2): 92&#8211;96)Wstęp: Ocena przydatności oznaczania krążącej IL-16 i RANTES jako wskaźników aktywności GO oraz określenie roli tych cytokin w patogenezie GO. Materiał i metody: 42 osoby w 4 grupach: 1 &#8212; 15 pacjentów z klinicznymi objawami orbitopatii w eutyreozie (GO), którzy poddali się leczeniu kortykosteroidami przy zastosowaniu podawanego dożylnie metylprednizolonu (MP) i teleradioterapii (TR); 2 &#8212; 10 pacjentów z chorobą Gravesa w nadczynności (Gtx); 3 &#8212; 10 pacjentów z chorobą Gravesa w eutyreozie (Geu); 4 &#8212; 7 zdrowych ochotników dobranych pod względem płci i wieku do grup 1.&#8211;3. Próbki krwi pobrano 24 h przed MP, 24 h po 1. dawce MP, przed TR i po zakończeniu leczenia. Stężenia IL-16 i RANTES w surowicy oznaczono metodą ELISA, a TSH-Rab &#8212; metodą RIA. Wyniki: Stężenie IL-16 w surowicy u pacjentów z GO było istotnie wyższe po zakończeniu terapii &#8212; 346 pg/ml (257&#8211;538) w porównaniu z wartością IL-16 przed leczeniem &#8212; 250 ng/ml (211&#8211;337) i w odniesieniu do grupy kontrolnej. Stężenie RANTES w surowicy nie różniło się istotnie między badanymi grupami i leczenie immunosupresyjne nie wpłynęło na jej wartość. Wykazano ujemną korelację między TSH-Rab i RANTES we wszystkich badanych grupach (R = &#8211;0,32; p < 0,01). Wnioski: Uzyskane dane wskazują, że IL-16 może wywierać immunomodulujący wpływ na przebieg orbitopatii. Zarówno oznaczenia IL-16, jak i RANTES w surowicy mogą być przydatne klinicznie, jednak ustalenie ich miejsca w diagnostyce i monitorowaniu leczenia GO wymaga dalszych badań. (Endokrynol Pol 2012; 63 (2): 92&#8211;96