- ID:
- ivo://CDS.VizieR/J/A+A/615/A8
- Title:
- APEX spectrum of R Dor (159.0-368.5GHz)
- Short Name:
- J/A+A/615/A8
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Our current insights into the circumstellar chemistry of asymptotic giant branch (AGB) stars are largely based on studies of carbon-rich stars and stars with high mass-loss rates. In order to expand the current molecular inventory of evolved stars we present a spectral scan of the nearby, oxygen-rich star R Dor, a star with a low mass-loss rate (~2x10^-7^M_{sun}_/yr). We carried out a spectral scan in the frequency ranges 159.0-321.5GHz and 338.5-368.5GHz (wavelength range 0.8-1.9mm) using the SEPIA/Band-5 and SHeFI instruments on the APEX telescope and we compare it to previous surveys, including one of the oxygen-rich AGB star IK Tau, which has a high mass-loss rate (~5x10^-6^M_{sun}_/yr). The spectrum of R Dor is dominated by emission lines of SO_2_ and the different isotopologues of SiO. We also detect CO, H_2_O, HCN, CN, PO, PN, SO, and tentatively TiO_2_, AlO, and NaCl. Sixteen out of approximately 320 spectral features remain unidentified. Among these is a strong but previously unknown maser at 354.2GHz, which we suggest could pertain to H_2_SiO, silanone. With the exception of one, none of these unidentified lines are found in a similarly sensitive survey of IK Tau performed with the IRAM 30 m telescope. We present radiative transfer models for five isotopologues of SiO (^28^SiO, ^29^SiO, ^30^SiO, Si^17^O, Si^18^O), providing constraints on their fractional abundance and radial extent. We derive isotopic ratios for C, O, Si, and S and estimate that, based on our results for ^17^O/^18^O, R Dor likely had an initial mass in the range 1.3-1.6M_{sun}_, in agreement with earlier findings based on models of H_2_O line emission. From the presence of spectral features recurring in many of the measured thermal and maser emission lines we tentatively identify up to five kinematical components in the outflow of R Dor, indicating deviations from a smooth, spherical wind.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/162/211
- Title:
- APF radial velocity follow up of {iota} Draconis
- Short Name:
- J/AJ/162/211
- Date:
- 14 Mar 2022 06:38:23
- Publisher:
- CDS
- Description:
- Giant stars as known exoplanet hosts are relatively rare due to the potential challenges in acquiring precision radial velocities and the small predicted transit depths. However, these giant host stars are also some of the brightest in the sky and so enable high signal-to-noise ratio follow-up measurements. Here, we report on new observations of the bright (V~3.3) giant star {iota}Draconis ({iota}Dra), known to host a planet in a highly eccentric ~511 day period orbit. TESS observations of the star over 137days reveal asteroseismic signatures, allowing us to constrain the stellar radius, mass, and age to ~2%, ~6%, and ~28%, respectively. We present the results of continued radial-velocity monitoring of the star using the Automated Planet Finder over several orbits of the planet. We provide more precise planet parameters of the known planet and, through the combination of our radial-velocity measurements with Hipparcos and Gaia astrometry, we discover an additional long-period companion with an orbital period of ~68_-36_^+60^yr. Mass predictions from our analysis place this substellar companion on the border of the planet and brown dwarf regimes. The bright nature of the star combined with the revised orbital architecture of the system provides an opportunity to study planetary orbital dynamics that evolve as the star moves into the giant phase of its evolution.
- ID:
- ivo://CDS.VizieR/J/ApJ/859/19
- Title:
- A^1^{Pi}-X^1^{Sigma}^+^ transitions of CO study
- Short Name:
- J/ApJ/859/19
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Highly correlated ab initio calculations were performed for an accurate determination of the A^1^{Pi}-X^1^{Sigma}^+^ system of the CO molecule. A highly accurate multi-reference configuration interaction approach was used to investigate the potential energy curves (PECs) and the transition dipole moment curve (TDMC). The resultant PECs and TDMC found by using the aug-cc-pV5Z (aV5Z) basis set and 5330 active spaces are in good agreement with the experimental data. Moreover, the Einstein A coefficients, lifetimes, ro-vibrational intensities, absorption oscillator strengths, and integrated cross sections are calculated so that the vibrational bands include v"=0-39 -> v'=0-23. For applications in the atmosphere and interstellar clouds, we studied the transition lineshapes to Gaussian and Lorentzian profiles at different temperatures and pressures. The intensities were calculated at high temperature that was used to satisfy some astrophysical applications, such as in planetary atmospheres. The results are potentially useful for important SAO/NASA Astrophysics Data System and databases such as HITRAN, HITEMP, and the National Institute of Standards and Technology. Because the results from many laboratory techniques and our calculations now agree, analyses of interstellar CO based on absorption from A^1^{Pi}-X^1^{Sigma}^+^ are no longer hindered by present spectral parameters.
- ID:
- ivo://CDS.VizieR/J/ApJ/840/81
- Title:
- A^3^{Pi}-X^3^{Sigma}^-^ transitions of OH+
- Short Name:
- J/ApJ/840/81
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The OH^+^ ion is of critical importance to the chemistry in the interstellar medium and is a prerequisite for the generation of more complex chemical species. Submillimeter and ultraviolet observations rely on high quality laboratory spectra. Recent measurements of the fundamental vibrational band and previously unanalyzed Fourier transform spectra of the near-ultraviolet A^3^{Pi}-X^3^{Sigma}^-^ electronic spectrum, acquired at the National Solar Observatory (NSO) at Kitt Peak in 1989, provide an excellent opportunity to perform a global fit of the available data. These new optical data are approximately four times more precise as compared to the previous values. The fit to the new data provides updated molecular constants, which are necessary to predict the OH^+^ transition frequencies accurately to support future observations. These new constants are the first published using the modern effective Hamiltonian for a linear molecule. These new molecular constants allow for easy simulation of transition frequencies and spectra using the PGOPHER program. The new constants improve simulations of higher J-value infrared transitions, and represent an improvement of an order of magnitude for some constants pertaining to the optical transitions.
- ID:
- ivo://CDS.VizieR/J/MNRAS/492/431
- Title:
- A planetary-mass companion to a solar-type star
- Short Name:
- J/MNRAS/492/431
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Young Suns Exoplanet Survey (YSES) consists of a homogeneous sample of 70 young, solar-mass stars located in the Lower Centaurus-Crux subgroup of the Scorpius-Centaurus association with an average age of 15+/-3Myr. We report the detection of a co-moving companion around the K3IV star TYC 8998-760-1 (2MASSJ13251211-6456207) that is located at a distance of 94.6+/-0.3pc using SPHERE/IRDIS on the VLT. Spectroscopic observations with VLT/X-SHOOTER constrain the mass of the star to 1.00+/-0.02M_{sun}_ and an age of 16.7+/-1.4Myr. The companion TYC 8998-760-1 b is detected at a projected separation of 1.71arcsec, which implies a projected physical separation of 162au. Photometric measurements ranging from Y to M band provide a mass estimate of 14+/-3M_Jup_ by comparison to BT-Settl and AMES-dusty isochrones, corresponding to a mass ratio of q=0.013+/-0.003 with respect to the primary. We rule out additional companions to TYC 8998-760-1 that are more massive than 12M_Jup_ and farther than 12au away from the host. Future polarimetric and spectroscopic observations of this system with ground and space based observatories will facilitate testing of formation and evolution scenarios shaping the architecture of the circumstellar environment around this 'young Sun'.
- ID:
- ivo://CDS.VizieR/J/MNRAS/269/151
- Title:
- APM cluster redshift survey
- Short Name:
- J/MNRAS/269/151
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present redshifts for a sample of 228 clusters selected from the APM Galaxy Survey, 188 of which are new redshift determinations. Redshifts are listed for 365 galaxies, and non-cluster galaxy redshifts have been rejected from this sample using a likelihood ratio test based on the projected and apparent magnitude distributions of each cluster region. We test this technique using clusters for which redshifts have been measured for more than 10 galaxies. Our redshift sample is nearly complete and has been used in previous papers to study the three-dimensional distribution of rich clusters of galaxies. 156 of the clusters in our sample are listed in the Abell catalogue or supplement, and the remainder are new cluster identifications.
- ID:
- ivo://CDS.VizieR/J/A+A/608/A30
- Title:
- APM 08279+5255 CO(4-3) spectrum
- Short Name:
- J/A+A/608/A30
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have performed a high sensitivity observation of the UFO/BAL quasar APM 08279+5255 at z=3.912 with NOEMA at 3.2mm, aimed at detecting fast moving molecular gas. We report the detection of blueshifted CO(4-3) with maximum velocity (v95%) of -1340km/s, with respect to the systemic peak emission, and a luminosity of L'=9.9x10^9^{mu}^-1^K.km/s/pc^2^, where {mu} is the lensing magnification factor. We discuss various scenarios for the nature of this emission and conclude that this is the first detection of fast molecular gas at redshift >3. We derived a mass flow rate of molecular gas in the range dM/dt=3-7.4x10^3^M_{sun}_/yr and momentum boost (dP_OF_/dt)/(dP_AGN_/dt)~2-6, which is therefore consistent with a momentum conserving flow. For the largest dP_OF_ the scaling is also consistent with an energy conserving flow with an efficiency of ~10-20%. The present data can hardly discriminate between the two expansion modes. The mass loading factor of the molecular outflow {eta}=(dM_OF_/dt)/SFR is >>1. We also detected a molecular emission line at a frequency of 94.83GHz corresponding to a rest-frame frequency of 465.8GHz; we tentatively identified this frequency with the cation molecule N_2_H^+^(5-4), which would be the first detection of this species at high redshift. We discuss the alternative possibility that this emission is due to a CO emission line from the, so far undetected, lens galaxy. Further observations of additional transitions of the same species with NOEMA can discriminate between the two scenarios.
- ID:
- ivo://CDS.VizieR/J/AJ/110/1032
- Title:
- APM elliptical galaxies radial velocities
- Short Name:
- J/AJ/110/1032
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present 292 new redshifts of elliptical galaxies selected from the APM Bright Galaxy Survey. We use these data together with published redshifts and bj apparent magnitudes from the APM Bright Galaxy Survey in order to estimate the shape of the Luminosity Function of a total sample of 535 ellipticals. We use the Maximum Likelihood method for the determination of the best fitting parameters {alpha} and M^*^ of a Schechter Function. In order to provide tests for systematics and suitable error estimates we apply Monte Carlo techniques which are also used to deal with incompleteness effects in the data. In agreement with other authors our results indicate a relative lack of low luminosity ellipticals compared to other morphological types. The best fitting shape parameters derived are {alpha}=0.20+/-0.25 and M^*^_Bj_=-20.0+/-0.3. We do not find evidence for a dependence of these parameters on environment.
- ID:
- ivo://CDS.VizieR/J/A+A/617/A118
- Title:
- APM 08279+5255 optical-to-UV spectrum
- Short Name:
- J/A+A/617/A118
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present the analysis of the rest-frame optical-to-UV spectrum of APM 08279+5255, a well-known lensed broad absorption line (BAL) quasar at z=3.911. The spectroscopic data are taken with the optical DOLoRes and near-IR NICS instruments at TNG, and include the previously unexplored range between CIII] {lambda}1910 and [OIII] {lambda}{lambda}4959,5007. We investigate the possible presence of multiple BALs by computing "balnicity" and absorption indexes (i.e. BI, BI_0_ and AI) for the transitions SiIV {lambda}1400, CIV {lambda}1549, AlIII {lambda}1860 and MgII {lambda}2800. No clear evidence for the presence of absorption features is found in addition to the already known, prominent BAL associated to C IV, which supports a high-ionization BAL classification for APM 08279+5255. We also study the properties of the [OIII], H{beta} and MgII emission lines. We find that [OIII] is intrinsically weak (F_[OIII]_/F_H{beta}_<~0.04), as it is typically found in luminous quasars with a strongly blueshifted CIV emission line (2500km/s for APM 08279+5255). We compute the single-epoch black hole mass based on MgII and H{beta} broad emission lines, finding M_BH_=(2/3)*10^10^{mu}^-1^M_{sun}_, with the magnification factor {mu} that can vary between 4 and 100 according to CO and rest-frame UV-to-mid-IR imaging respectively. Using a MgII equivalent width (EW)-to-Eddington ratio relation, the EW_MgII_~27{AA} measured for APM 08279+5255 translates into an Eddington ratio of ~0.4, which is more consistent with {mu}=4. This magnification factor also provides a value of M_BH_ that is consistent with recent reverberation-mapping measurements derived from CIV and SiIV.
- ID:
- ivo://CDS.VizieR/J/AJ/156/94
- Title:
- APOGEE and Gaia DR2 analysis of IC 166
- Short Name:
- J/AJ/156/94
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- IC 166 is an intermediate-age open cluster (OC) (~1 Gyr) that lies in the transition zone of the metallicity gradient in the outer disk. Its location, combined with our very limited knowledge of its salient features, make it an interesting object of study. We present the first high-resolution spectroscopic and precise kinematical analysis of IC 166, which lies in the outer disk with R_GC_~12.7 kpc. High-resolution H-band spectra were analyzed using observations from the SDSS-IV Apache Point Observatory Galactic Evolution Experiment survey. We made use of the Brussels Automatic Stellar Parameter code to provide chemical abundances based on a line-by-line approach for up to eight chemical elements (Mg, Si, Ca, Ti, Al, K, Mn, and Fe). The {alpha}-element (Mg, Si, Ca, and whenever available Ti) abundances, and their trends with Fe abundances have been analyzed for a total of 13 high-likelihood cluster members. No significant abundance scatter was found in any of the chemical species studied. Combining the positional, heliocentric distance, and kinematic information, we derive, for the first time, the probable orbit of IC 166 within a Galactic model including a rotating boxy bar, and found that it is likely that IC 166 formed in the Galactic disk, supporting its nature as an unremarkable Galactic OC with an orbit bound to the Galactic plane.
