European Southern Observatory

About: European Southern Observatory is a facility organization based out in Garching bei München, Germany. It is known for research contribution in the topics: Galaxy & Stars. The organization has 3594 authors who have published 16157 publications receiving 823095 citations. The organization is also known as: The European Southern Observatory，ESO & ESO.

ATLASGAL – environments of 6.7 GHz methanol masers

Abstract: Using the 870 μm APEX Telescope large area survey of the Galaxy, we have identified 577 submillimetre continuum sources with masers from the methanol multibeam survey in the region 280° 20 M. Furthermore, almost all clumps satisfy the empirical mass-size criterion for massive star formation. Bolometric luminosities taken from the literature for ∼100 clumps range between ∼100 and 10 L. This confirms the link between methanol masers and massive young stars for 90 per cent of our sample. The Galactic distribution of sources suggests that the star formation efficiency is significantly reduced in the Galactic Centre region, compared to the rest of the survey area, where it is broadly constant, and shows a significant drop in the massive star formation rate density in the outer Galaxy. We find no enhancement in source counts towards the southern Scutum-Centaurus arm tangent at l ∼ 315°, which suggests that this arm is not actively forming stars. © 2013 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society.

Colors of Minor Bodies in the Outer Solar System ?;?? A statistical analysis

Abstract: We present a compilation of all available colors for 104 Minor Bodies in the Outer Solar System (MBOSSes); for each object, the original references are listed The measurements were combined in a way that does not introduce rotational color artifacts We then derive the slope, or reddening gradient, of the low resolution reflectance spectra obtained from the broad-band color for each object A set of color-color diagrams, histograms and cumulative probability functions are presented as a reference for further studies, and are discussed In the color-color diagrams, most of the objects are located very close to the \reddening line" (corresponding to linear reflectivity spectra) A small but systematic deviation is observed toward the I band indicating a flattening of the reflectivity at longer wavelengths, as expected from laboratory spectra A deviation from linear spectra is noticed toward the B for the bluer objects; this is not matched by laboratory spectra of fresh ices, possibly suggesting that these objects could be covered with extremely evolved/irradiated ices Five objects (1995 SM55, 1996 TL66, 1999 OY3, 1996 TO66 and (2060) Chiron) have almost perfectly solar colors; as two of these are known or suspected to harbour cometary activity, the others should be searched for activity or fresh ice signatures In the color-color diagrams, 1994 ES2, 1994 EV3, 1995 DA2 and 1998 HK151 are located very far from the main group of objects; it is suspected that this corresponds to inaccurate measurements and not intrinsically strange objects The color distributions were analyzed as functions of the orbital parameters of the objects and of their absolute magnitude No signicant correlation is observed, with the following exceptions: Cubewanos with low orbital excitation (lowi,e and/orE = p e 2 +s in 2 i), and therefore experiencing on average fewer and less violent collisions have signicantly redder colors; Cubewanos with faint absolute magnitude M(1; 1) tend to be redder than the others, while Plutinos present the opposite trend The color distribution of the various MBOSS classes are analyzed and compared using generic statistic tools The comets were found to be signicantly bluer than the other MBOSSes Finally, we compare the various 1D and 2D color distributions to simple models, in order to throw some light on the question of the bimodality of MBOSS color distributions It is found that with the current data set, all color distributions are compatible with simple, continuous distribution models, while some color distributions are not compatible with simple bimodal distribution models Table 1 is also available in electronic form at the CDS via anonymous ftp to cdsarcu-strasbgfr (130791285) or via http://cdswebu-strasbgfr/cgi-bin/qcat?J/A+A/389/641, and the tables and complete set of gures corresponding the up-to-date database are available on the web at http://wwwscesoorg/~ohainaut/MBOSS

The CORALIE survey for southern extra-solar planets - XIII. A pair of planets around HD 202206 or a circumbinary planet?

Abstract: Long-term precise Doppler measurements with the CORALIE spectrograph reveal the presence of a second planet orbiting the solar-type star HD 202206. The radial-velocity combined fit yields companion masses of m2 sin i = 17.4 MJup and 2.44 MJup, semi-major axes of a = 0.83 AU and 2.55 AU, and eccentricities of e = 0.43 and 0.27, respectively. A dynamical analysis of the system further shows a 5/1 mean motion resonance between the two planets. This system is of particular interest since the inner planet is within the brown-dwarf limits while the outer one is much less massive. Therefore, either the inner planet formed simultaneously in the protoplanetary disk as a superplanet, or the outer Jupiter-like planet formed in a circumbinary disk. We believe this singular planetary system will provide important constraints on planetary formation and migration scenarios.

Optical and Infrared Spectroscopy of SN 1999ee and SN 1999ex

Abstract: We report optical and infrared spectroscopic observations of the Type Ia SN 1999ee and the Type Ib/c SN 1999ex, both of which were hosted by the galaxy IC 5179. For SN 1999ee we obtained a continuous sequence with an unprecedented wavelength and temporal coverage beginning 9 days before maximum light and extending through day 42. Before maximum light SN 1999ee displayed a normal spectrum with a strong Si II λ6355 absorption, thus showing that not all slow-declining supernovae (SNe) are spectroscopically peculiar at these evolutionary phases. A comparative study of the infrared spectra of SN 1999ee and other Type Ia SNe shows that there is a remarkable homogeneity among the Branch-normal SNe Ia during their first 60 days of evolution. SN 1991bg–like objects, on the other hand, display spectroscopic peculiarities at infrared wavelengths. SN 1999ex was characterized by the lack of hydrogen lines, weak optical He I lines, and strong He I λλ10830, 20581, thus providing an example of an intermediate case between pure Ib and Ic supernovae. We conclude, therefore, that SN 1999ex provides the first clear evidence for a link between the Ib and Ic classes and that there is a continuous spectroscopic sequence ranging from the He-deficient SNe Ic to the SNe Ib, which are characterized by strong optical He I lines.

The FIRST Radio-loud Broad Absorption Line QSO and Evidence for a Hidden Population of Quasars

Abstract: We have discovered two low-ionization broad absorption line (BAL) quasars in programs to obtain optical spectra for radio-selected quasar candidates from the VLA Faint Images of the Radio Sky at Twenty Centimeters (FIRST) Survey. Both belong to the extremely rare class of BAL QSOs that exhibit narrow absorption lines from metastable excited levels of Fe II and Fe III. Until now, there was just a single object in this class, 0059-2735. In addition, one of our new objects is the first known radio-loud BAL QSO. The properties of these three unusual objects suggest a trend of increasing radio luminosity with the amount of absorption to the quasar, and are perhaps transition objects between radio-loud and radio-quiet quasars. The two new objects are from a radio-selected sample comprising less than 200 quasars; one is heavily attenuated at optical wavelengths in the observed frame. These objects would be easily overlooked by most optical QSO searches; their abundance in the radio sample suggests that they may be representatives of a largely undetected component of the quasar population, perhaps as numerous as ordinary low-ionization BAL QSOs, which constitute 1%-2% of all QSOs.