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- ID:
- ivo://CDS.VizieR/J/A+AS/109/551
- Title:
- Stark broadening. XII. OIV & OV
- Short Name:
- J/A+AS/109/551
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/A+AS/119/369
- Title:
- Stark broadening. XIV: Be III and B III
- Short Name:
- J/A+AS/119/369
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using a semiclassical approach, we have calculated electron-, proton-, and ionized helium-impact line widths and shifts for 12 Be III and 27 B III multiplets. The obtained results have been compared with available experimental and theoretical data.
- ID:
- ivo://CDS.VizieR/J/PAZh/23/931
- Title:
- Star kinematics catalog in 19 Kapteyn's areas
- Short Name:
- J/PAZh/23/931
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- 1214 individual measurements of radial velocities made with CORAVEL-type spectrometer (Tokovinin, 1987AZh....64..196T) are presented for 1134 stars in 19 northern Kapteyn's areas. Precise coordinates are given for all these stars. Proper motions of stars are taken from NLTT (Luyten, 1979, Cat. <I/98>), PPM (Roser, Bastian, 1991, Cat. <I/146> and <I/193>), NPM1 (Klemola, Hanson, Jones, 1987, Cat. <I/200>) and Four-million catalog (Kuimov, 1992, In: On the four-million catalog of stars, eds. Izd. MGU, Moscow, P.27.; Glushkova et al., 1996PAZh...22..850G). A list of suspected binary stars and stars with variable radial velocities is also given. Two-dimensional spectral classification for these area is available (Bartaya, 1979AbaOB..51....1B).
17875. Stark widths of FeII lines
- ID:
- ivo://CDS.VizieR/J/A+AS/102/607
- Title:
- Stark widths of FeII lines
- Short Name:
- J/A+AS/102/607
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Stark widths of singly ionized iron lines from a^6^D--z^6^D^o^ and a^6^D--z^6^F^o^ have been measured and compared with the predictions obtained on the basis of the Stark broadening regularities within similar spectra. The measurements were performed using a linear arc discharge plasma source within an electron density range of 5x10^22^m^-3^--2x10^23^m^-3^ and an electron temperature from 27000K to 30000K.
17876. Starless clumps in ATLASGAL
- ID:
- ivo://CDS.VizieR/J/A+A/540/A113
- Title:
- Starless clumps in ATLASGAL
- Short Name:
- J/A+A/540/A113
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Understanding massive star formation requires comprehensive knowledge about the initial conditions of this process. The cradles of massive stars are believed to be located in dense and massive molecular clumps. In this study, we present an unbiased sample of the earliest stages of massive star formation across 20deg^2^ of the sky. Within the region 10{deg}<l<20{deg} and |b|<1{deg}, we search the ATLASGAL survey at 870um for dense gas condensations. These clumps are carefully examined for indications of ongoing star formation using YSOs from the GLIMPSE source catalog as well as sources in the 24um MIPSGAL images, to search for starless clumps. We calculate the column densities as well as the kinematic distances and masses for sources where the v_lsr_ is known from spectroscopic observations. Within the given region, we identify 210 starless clumps with peak column densities >10^23^cm^-2^. In particular, we identify potential starless clumps on the other side of the Galaxy. The sizes of the clumps range between 0.1pc and 3pc with masses between a few tens of M_{sun}_ up to several ten thousands of M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/A+A/630/A136
- Title:
- Starless core L1521E chemical structure
- Short Name:
- J/A+A/630/A136
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have obtained ~2.5x2.5 arcminute maps toward L1521E using the IRAM-30m telescope in transitions of various species, including C^17^O, CH_3_OH c-C_3_H_2_, CN, SO, H_2_CS, and CH_3_CCH. We derived abundances for the observed species and compared them to those obtained toward L1544. We estimated CO depletion factors using the C^17^O IRAM-30m map, an N(H2) map derived from Herschel/ SPIRE data and a 1.2 mm dust continuum emission map obtained with the IRAM-30m telescope. Similarly to L1544, c-C_3_H_2_ and CH_3_OH peak at different positions. Most species peak toward the c-C_3_H_2_ peak: C_2_S, C_3_S, HCS^+^, HC_3_N, H_2_CS, CH_3_CCH, C^34^S. C^17^O and SO peak close to both the c-C_3_H_2_ and the CH_3_OH peaks. CN and N_2_H^+^ peak close to the Herschel dust peak. We found evidence of CO depletion toward L1521E. The lower limit of the CO depletion factor derived toward the Herschel dust peak is 4.3+/-1.6, which is about a factor of three lower than toward L1544. We derived abundances for several species toward the dust peaks of L1521E and L1544. The abundances of most sulfur-bearing molecules such as C_2_S, HCS^+^, C^34^S, C^33^S, and HCS^+^ are higher toward L1521E than toward L1544 by factors of ~2-20, compared to the abundance of A-CH_3_OH. The abundance of methanol is very similar toward the two cores.
- ID:
- ivo://CDS.VizieR/J/A+A/643/A60
- Title:
- Starless cores CH_3_OH and c-C_3_H_2_ maps
- Short Name:
- J/A+A/643/A60
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The spatial distribution of molecules around starless cores is a powerful tool for studying the physics and chemistry governing the earliest stages of star formation. Our aim is to study the chemical differentiation in starless cores to determine the influence of large-scale effects on the spatial distribution of molecules within the cores. Furthermore, we want to put observational constraints on the mechanisms responsible in starless cores for the desorption of methanol from the surface of dust grains where it is efficiently produced. We mapped methanol, CH_3_OH, and cyclopropenylidene, c-C_3_H_2_, with the IRAM 30m telescope in the 3mm band towards six starless cores embedded in different environments, and in different evolutionary stages. Furthermore, we searched for correlations among physical properties of the cores and the methanol distribution. From our maps we can infer that the chemical segregation between CH_3_OH and c-C_3_H_2_ is driven by uneven illumination from the interstellar radiation field (ISRF). The side of the core that is more illuminated has more C atoms in the gas-phase and the formation of carbon-chain molecules like c-C3H2 is enhanced. Instead, on the side that is less exposed to the ISRF the C atoms are mostly locked in carbon monoxide, CO, the precursor of methanol. We conclude that large-scale effects have a direct impact on the chemical segregation that we can observe at core scale. However, the non-thermal mechanisms responsible for the desorption of methanol in starless cores do not show any dependency on the H_2_ column density at the methanol peak.
- ID:
- ivo://CDS.VizieR/J/ApJS/153/523
- Title:
- Starless cores in CS(3-2) and DCO^+^(2-1) lines
- Short Name:
- J/ApJS/153/523
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present CS(3-2) and DCO^+^(2-1) observations of 94 starless cores and compare the results with previous CS(2-1) and N_2_H^+^(1-0) observations to study inward motions in starless cores. Eighty-four cores were detected in both CS and DCO^+^ lines. We identify 18 infall candidates based on observations of CS(3-2), CS(2-1), DCO^+^(2-1) and N_2_H^+^(1-0). The eight best candidates, L1355, L1498, L1521F, L1544, L158, L492, L694-2, and L1155C-1, each show at least four indications of infall asymmetry and no counterindications. Fits of the spectra to a two-layer radiative transfer model in ten infall candidates suggest that the median effective line of sight speed of the inward-moving gas is ~0.07km/s for CS(3-2) and ~0.04km/s for CS(2-1).
17880. Starless cores in HCN(J=1-0)
- ID:
- ivo://CDS.VizieR/J/ApJ/664/928
- Title:
- Starless cores in HCN(J=1-0)
- Short Name:
- J/ApJ/664/928
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a survey toward the central regions of 85 starless cores in HCN(J=1-0) to study inward motions in the cores. Sixty-four cores were detected with HCN lines. The infall asymmetry in the HCN spectra is found to be more prevalent, and more prominent than in any other previously used infall tracers such as CS(J=2-1), DCO^+^(J=2-1), and N2H^+^(J=1-0). We have found a close relation between the intensities of the HCN and N2H^+^ lines.