We present spectroscopic and photometric analysis of the quintuple star HD 86222 with an eclipsing component. Until now three visual components A, B, and C of this multiple star were known. Four components in the A/B pair were detected during the examination of the cross correlation functions obtained from the spectra.
The binary star HD 45166 has been observed since 1922 but its orbital period has not yet been found. It is considered a peculiar Wolf-Rayet star, and its assigned classification has varied. For this reason we included the object as a candidate V Sge star and performed spectroscopy in order to search for its putative orbital period. High-resolution spectroscopic observations show that the spectrum, in emission and in absorption, is quite rich. The emission lines have great diversity of widths and profiles. The full widths at half maximum vary from 70km/s for the weakest lines up to 370km/s for the most intense ones. The Hydrogen and Helium lines are systematically broader than the CNO lines. Assuming that HD 45166 is a double-line spectroscopic binary, it present s an orbital period of P=1.596+/-0.003-day, with an eccentricity of e=0.18+/-0.08. In addition, a search for periodicity using standard techniques reveals that the emission lines present at least two other periods, of 5 and 5 hour. The secondary star has a spectral type of B7 V and, therefore, should have a mass of about M=4.8M_{sun}_. Given the radial velocity amplitudes, we determined the mass of the hot (primary) star as M=4.2+/-0.7M_{sun}_ and the inclination angle of the system, i=0.77+/-0.09deg. As the eccentricity of the orbit is non zero, the Roche lobes increase and decrease as a function of the orbital phase. At periastron, the secondary star fills its Roche lobe. The distance to the star has been re-determined as d=1.3+/-0.2kpc and a color excess of E(B-V)=0.155+/-0.007 has been derived. This implies an absolute B magnitude of -0.6 for the primary star and -0.7 for the B7 star. We suggest that the discrete absorption components (DACs) observed in the ultraviolet with a periodicity similar to the orbital period may be induced by periastron events.
On the basis of spectroscopic CCD material obtained at the Haute Provence Observatory, we provide line identifications and equivalent width measurements in the wavelength regions 3750-5112 and 7065-10212{AA} of the spectrum of HD 45677. Over 235 features are identified and a comparison of our results with those of other authors is provided. We also discuss the variability of the lines using equivalent widths and the line spectrum. We conclude that the gaseous shell surrounding the star has a temperature of the order of 7000K and that its distance to the star is less than ten stellar radii. We discuss the similarity of this star to other stars previously analyzed.
We analyse CCD spectroscopic material obtained at the Haute Provence Observatory between 1990 and 1993, covering the wavelength region 380-1100mm. 320 emission lines were measured and identified. Of these about 40% correspond to permitted or forbidden lines of ionized iron. Many forbidden lines (20% of the total) are present, including many classic nebular lines. We also provide a comparison of our results with those of other authors. The equivalent width measurements permit to follow in detail the variations of the lines of several elements over the three years and to compare them to variations reported by other authors. On our material the largest variations correspond to helium, which varied by a factor of two and are not in phase with the variations of hydrogen. Many helium lines exhibit P Cyg type profiles, indicating strong outflow of matter from the star. The lines of other elements follow either the variations of the helium or of the hydrogen lines. The radial velocity varies over the years, with an amplitude of more than 60km/s.
We present Herschel PACS spectroscopic observations of the [CII] 157um, [OI] 63 and 145um, [OIII] 88um, [NII] 122 and 205um, and [NIII] 57um fine-structure cooling lines in a sample of 48 low-metallicity star-forming galaxies of the guaranteed time key program Dwarf Galaxy Survey. We correlate PACS line ratios and line-to-LTIR ratios with LTIR, LTIR/LB, metallicity, and FIR color, and interpret the observed trends in terms of ISM conditions and phase filling factors with Cloudy radiative transfer models. We find that the ISM of low-metallicity dwarf galaxies has a more porous structure than that of metal-rich galaxies. The radiation fields are harder and the the ionized gas/PDR filling factor is larger in the dwarfs.
In this work we analyze the spectroscopic properties of a large number of HII regions, ~2600, located in 38 galaxies. The sample of galaxies has been assembled from the face-on spirals in the PINGS survey and a sample described in Marmol-Queralto (2011A&A...534A...8M). All the galaxies were observed using Integral Field Spectroscopy with a similar setup, covering their optical extension up to ~2.4 effective radii within a wavelength range from ~3700 to ~6900{AA}. We develop a new automatic procedure to detect HII regions, based on the contrast of the H{alpha} intensity maps extracted from the datacubes. Once detected, the procedure provides us with the integrated spectra of each individual segmented region. In total, we derive good quality spectroscopic information for ~2600 independent HII regions/complexes. This is by far the largest nearby 2-dimensional spectroscopic survey presented on this kind of regions up-to-date. Even more, our selection criteria and dataset guarantee that we cover the regions in an unbiased way, regarding the spatial sampling. A well-tested automatic decoupling procedure has been applied to remove the underlying stellar population, deriving the main properties (intensity, dispersion and velocity) of the strongest emission lines in the considered wavelength range (covering from [OII]3727 to [SII]6731). A final catalogue of the spectroscopic properties of these regions has been created for each galaxy.
Optical and near-infrared spectroscopy of molecular hydrogen in interstellar shocks provide a very powerful probe of the physical conditions that prevail in interstellar shocks. Integral-field spectroscopy of H_2_ in the optical wavelength region and complementary long-slit near-infrared spectroscopy towards HH91A are used to characterize the ro-vibrational population distribution among H_2_ levels with excitation energies up to 30000cm^-1^.
The INTEGRAL hard X-ray observatory has revealed an emerging population of highly obscured X-ray binary systems through multi-wavelength observations. Previous studies have shown that many of these sources are high-mass X-ray binaries hosting neutron stars orbiting around luminous and evolved companion stars. To better understand this newly-discovered population, we have selected a sample of sources for which an accurate localisation is available to identify the stellar counterpart and reveal the nature of the companion star and of the binary system.
Emission-line spectra extracted at multiple locations across 39 ultraluminous infrared galaxies have been compiled into a spectrophotometric atlas. Line profiles of H{alpha}, [NII], [SII], [OI], H{beta}, and [OIII] are resolved and fit jointly with common velocity components. Diagnostic ratios of these line fluxes are presented in a series of plots, showing how the Doppler shift, line width, gas excitation, and surface brightness change with velocity at fixed position and also with distance from the nucleus. One general characteristic of these spectra is the presence of shocked gas extending many kiloparsecs from the nucleus. In some systems, the rotation curves of the emitting gas indicate motions that suggest gas disks, which are most frequent at early merger stages. At these early merger stages, the emission line ratios indicate the presence of shocked gas, which may be triggered by the merger event. We also report the general characteristics of the integrated spectra.
A high resolution optical spectrum of the post-red supergiant candidate IRC +10420 is presented. The Utrecht Echelle Spectrograph observations, with a total integration time of more than 9 hours provide a spectral coverage from 3850 A to 1micron, and a spectral resolution of 9km/s. The spectrum is shown, and an identification list of lines in the spectrum is provided. From a preliminary analysis of the spectrum we find that the spectral type of IRC+10420 has changed from F8I+ in 1973 to mid- to early A type now, confirming the results of Oudmaijer et al. (1996MNRAS.280.1062O), who claimed a change in temperature based on photometric changes. It is shown that most of the emission lines in the spectrum of IRC +10420 are blue-shifted with respect to the systemic velocity traced by circumstellar rotational CO emission, while the (few) absorption lines - with the exception of some high excitation lines - are red-shifted by 25km/s, which may suggest infall of material onto the star. Finally, it is found that the interstellar extinction towards IRC +10420, as traced by the Diffuse Interstellar Bands is very large, with an inferred E(B-V) of 1.4+/-0.5 compared to a total E(B-V) of 2.4. This table provides the line identifications for the measured spectral lines from atomic species. Listed in the table are respectively the laboratory wavelength (in air) taken from Moore (1945, in A multiplet table of astrophysical interest, Contribution from the Princeton University Observatory No. 20.), the line identification (ion and multiplet), the energies of the lower levels of the transitions in eV, and the log(gf). The latter two values are taken from Wiese et al. (1966, Nat. Stand. Ref. Data Ser. 20 and 1969, Nat. Stand. Ref. Data Ser. 22), Martin et al. (1988, Cat. <VI/72>) and Fuhr et al. (1988, Cat. <VI/72>). The spectral lines that are marked `UN' were not identified, the wavelength given for these lines is the observed wavelength. Then next entries in the table are the velocity shift of the centres of spectral lines (in LSR), the equivalent width in milli-Angstrom, and the full-width-at-half maximum of the fit in Angstrom. The velocity shifts have been measured by fitting Gaussian profiles through the lines, the equivalent widths have been measured by integrating the line over the continuum. In the case of overlapping lines, the lines were de-composed by fitting multiple Gaussian components to the profiles. In these cases (marked with `deb.' in the table) the equivalent widths are the areas under the Gaussian fits. Equivalent widths for lines that could not be deblended, are given between brackets. These values represent the total equivalent width of the lines concerned.