- ID:
- ivo://CDS.VizieR/J/MNRAS/361/1102
- Title:
- Spectrum of {epsilon} Eri
- Short Name:
- J/MNRAS/361/1102
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Measurements of ultraviolet line fluxes from Space Telescope Imaging Spectrograph and Far-Ultraviolet Spectroscopic Explorer spectra of the K2-dwarf eps Eri are reported. These are used to develop new emission measure distributions and semi-empirical atmospheric models for the chromosphere and lower transition region of the star. These models are the most detailed constructed to date for a main-sequence star other than the Sun. New ionization balance calculations, which account for the effect of finite density on dielectronic recombination rates, are presented for carbon, nitrogen, oxygen and silicon. The results of these calculations are significantly different from the standard Arnaud & Rothenflug ion balance, particularly for alkali-like ions. The new atmospheric models are used to place constraints on possible first ionization potential (FIP)-related abundance variations in the lower atmosphere and to discuss limitations of single-component models for the interpretation of certain optically thick line fluxes.
Number of results to display per page
Search Results
2652. Spectrum of KQ Pup
- ID:
- ivo://CDS.VizieR/J/A+A/258/423
- Title:
- Spectrum of KQ Pup
- Short Name:
- J/A+A/258/423
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- (no description available)
- ID:
- ivo://CDS.VizieR/J/A+A/546/L3
- Title:
- Spectrum of LSR J0745+2627
- Short Name:
- J/A+A/546/L3
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report the identification of LSR J0745+2627 in the United Kingdom InfraRed Telescope Infrared Deep Sky Survey (UKIDSS) Large Area Survey (LAS) as a cool white dwarf with kinematics and age compatible with the thick-disk/halo population. LSR J0745+2627 has a high proper motion (890mas/yr) and a high reduced proper motion value in the J band (H_J=21.87). We show how the infrared-reduced proper motion diagram is useful for selecting a sample of cool white dwarfs with low contamination. LSR J0745+2627 is also detected in the Sloan Digital Sky Survey (SDSS) and the Wide-field Infrared Survey Explorer (WISE). We have spectroscopically confirmed this object as a cool white dwarf using X-Shooter on the Very Large Telescope. An analysis of its spectral energy distribution reveals that its atmosphere is compatible with a pure-H composition model with an effective temperature of 3880+/-90K. This object is the brightest pure-H ultracool white dwarf (Teff<4000K) ever identified. We have constrained the distance (24-45pc), space velocities and age considering different surface gravities. The results obtained suggest that LSR J0745+2627 belongs to the thick-disk/halo population and is also one of the closest ultracool white dwarfs.
- ID:
- ivo://CDS.VizieR/J/A+A/538/A119
- Title:
- Spectrum of ^18^O-methyl formate (HCO^18^OCH_3_)
- Short Name:
- J/A+A/538/A119
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Astronomical survey of interstellar molecular clouds needs a previous analysis of the spectra in the microwave and sub-mm energy range of organic molecules in order to be able to identify them. Very accurate spectroscopic constants are obtained in a comprehensive laboratory analysis of rotational spectra. These constants can be used to predict with very high precision the frequencies of transitions that have not been measured in the laboratory. In this work, an experimental study and its theoretical analysis is presented for two ^18^O-methyl formate isotopologues in order to detect for the first time both isotopologues in Orion KL. The experimental spectra of both isotopologues of methyl formate have been recorded in the microwave and sub-mm energy range from 1 to 660GHz. Both spectra have been analysed by using the Rho-Axis Method (RAM) which takes into account the CH3 internal rotation. Spectroscopic constants of both ^18^O-methyl formate have been obtained with high accuracy. Thousands of transitions were assigned and others predicted, which allowed us to detect both species in the IRAM 30m line survey of Orion KL for the first time in the space.
- ID:
- ivo://CDS.VizieR/J/A+A/605/A76
- Title:
- Spectrum of Orion KL between 41.5 and 50GHz
- Short Name:
- J/A+A/605/A76
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We resent a sensitive spectral survey of Orion KL in Q-band (7mm), made with one of the 34m antennas of the Madrid Deep Space Communications Complex in Robledo de Chavela, Spain.
- ID:
- ivo://CDS.VizieR/J/A+A/578/A11
- Title:
- Spectrum of QSO XMMC 2028
- Short Name:
- J/A+A/578/A11
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Gas outflows are believed to play a pivotal role in shaping galaxies, as they regulate both star formation and black hole growth. Despite their ubiquitous presence, the origin and the acceleration mechanism of such powerful and extended winds is not yet understood. Direct observations of the cold gas component in objects with detected outflows at other wavelengths are needed to assess the impact of the outflow on the host galaxy interstellar medium (ISM). We observed with the Plateau de Bure Interferometer an obscured quasar at z Gas outflows are believed to play a pivotal role in shaping galaxies, as they regulate both star formation and black hole growth. Despite their ubiquitous presence, the origin and the acceleration mechanism of such powerful and extended winds is not yet understood. Direct observations of the cold gas component in objects with detected outflows at other wavelengths are needed to assess the impact of the outflow on the host galaxy interstellar medium (ISM). We observed with the Plateau de Bure Interferometer an obscured quasar at z~1.5, XID2028, for which the presence of an ionised outflow has been unambiguously signalled by NIR spectroscopy. The detection of ^12^CO(3-2) emission in this source allows us to infer the molecular gas content and compare it to the ISM mass derived from the dust emission. We then analyze the results in the context of recent insights on scaling relations, which describe the gas content of the overall population of star-forming galaxies at a similar redshifts.
2657. Spectrum of SXP1062
- ID:
- ivo://CDS.VizieR/J/A+A/556/A139
- Title:
- Spectrum of SXP1062
- Short Name:
- J/A+A/556/A139
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Be/X-ray binary SXP 1062 is of especial interest owing to the large spin period of the neutron star, its large spin-down rate, and the association with a supernova remnant constraining its age. This makes the source an important probe for accretion physics. To investigate the long-term evolution of the spin period and associated spectral variations, we performed an XMM-Newton target-of-opportunity observation of SXP 1062 during X-ray outburst. Spectral and timing analysis of the XMM-Newton data was compared with previous studies, as well as complementary Swift/XRT monitoring and optical spectroscopy with the SALT telescope were obtained. The spin period was measured to be Ps=(1071.01+/-0.16)s on 2012 Oct 14. The X-ray spectrum is similar to that of previous observations. No convincing cyclotron absorption features, which could be indicative for a high magnetic field strength, are found. The high-resolution RGS spectra indicate the presence of emission lines, which may not completely be accounted for by the SNR emission. The comparison of multi-epoch optical spectra suggest an increasing size or density of the decretion disc around the Be star. SXP 1062 showed a net spin-down with an average of dPs/dt=(2.27+/-0.44)s/yr over a baseline of 915 days.
- ID:
- ivo://CDS.VizieR/J/MNRAS/447/817
- Title:
- Spectrum of the planetary nebula NGC 6210
- Short Name:
- J/MNRAS/447/817
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- High-resolution spectroscopy of NGC 6210, show that recombination line abundances of O^+2^ and Ne^+2^ are two to three times larger than forbidden line abundances, T_e_(O^+2^) is smaller than T_e_(N^+^) and possibly T_e_(S^+^), the ionized mass is ~0.07 M_{sun}_ and the progenitor zero-age main-sequence mass is 1.2-2 M_{sun}_. If electrons are in equilibrium, recombination lines are likely produced in a cold low-density medium. A photoionization model (cloudy 13.03) with a positive density gradient and two exciting sources, reproduced most of the optical spectrum, the temperature distribution of the nebula, HeII 4686/HeI 5876, [OII]3726/[OIII]5007 and [OII]3726/3729, but not the other density sensitive line ratios. Including fluorescence and recombination, we found good agreement with observed CII and CIII line intensities, OII and OIII model intensities which are 2.6 and 7.8 times smaller than observed and large erratic differences with observations in CIII, NII and NIII lines. UV and IR data suggest that [OII] emission is from a region ~6 times less dense than assumed by the model and that IR lines are produced in a medium where the density is ~1000/cm^3^. There may be a lower density medium beyond a dense ring described by the photoionization model, as well as a cold low-density component. A multicomponent model is required to reproduce the entire spectrum of NGC 6210.
- ID:
- ivo://CDS.VizieR/J/A+A/578/A75
- Title:
- Spectrum of V4332 Sgr in 2005
- Short Name:
- J/A+A/578/A75
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- V4332 Sgr is a red transient (red nova) whose eruption was observed in 1994. The remnant of the eruption shows a unique optical spectrum: strong emission lines of atomes and molecules superimposed on a M-type stellar spectrum. The stellar-like remnant is presumably embedded in a disc-like dusty envelope orientated almost face-on. The observed optical spectrum is supposed to result from interactions of the central-star radiation with dust and gas in the disc and outflows initiated in 1994. We have reduced and measured a high-resolution (R~40000) spectrum of V4332 Sgr obtained with VLT/UVES in April/May 2005. The spectrum comes from the ESO archives and is the best quality spectrum of the object ever obtained. We have identified and measured over 200 emission features belonging to 11 elements and 6 molecules. The continuous, stellar-like component can be classified as ~M3. The radial velocity of the object, as derived from narrow atomic emission line, is -75km/s. The interstellar reddening was estimated as being 0.35<E(B-V)<0.75. From radial velocities of interstellar absorption features in the NaI D lines we have estimated a lower limit of ~5.5 kpc to the distance of V4332 Sgr. When compared to spectroscopic observations done in 2009, the spectrum of V4332 Sgr considerably evolved between 2005 and 2009. The object significantly faded in the optical (by ~2mag in the V band), which resulted from the main remnant cooled by 300-350K corresponding to its spectral type changed from M3 to M5-6. The object however increased in luminosity by ~50%, implying a significant expansion of its dimensions. Most of the emission features seen in 2005 significantly faded or even disappeared from the spectrum of V4332 Sgr in 2009.
- ID:
- ivo://CDS.VizieR/J/ApJS/220/16
- Title:
- SpeX NIR survey of 886 nearby M dwarfs
- Short Name:
- J/ApJS/220/16
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a catalog of near-infrared (NIR) spectra and associated measurements for 886 nearby M dwarfs. The spectra were obtained with the NASA-Infrared Telescope Facility SpeX Spectrograph during a two-year observing campaign; they have high signal-to-noise ratios (S/N>100-150), span 0.8-2.4{mu}m, and have R~2000. Our catalog of measured values contains useful T_eff_ and composition-sensitive features, empirical stellar parameter measurements, and kinematic, photometric, and astrometric properties compiled from the literature. We focus on measurements of M dwarf abundances ([Fe/H] and [M/H]), capitalizing on the precision of recently published empirical NIR spectroscopic calibrations. We explore systematic differences between different abundance calibrations, and from other similar M dwarf catalogs. We confirm that the M dwarf abundances we measure show the expected inverse dependence with kinematic-, activity-, and color-based age indicators. Finally, we provide updated [Fe/H] and [M/H] for 16 M dwarf planet hosts. This catalog represents the largest published compilation of NIR spectra and associated parameters for M dwarfs. It provides a rich and uniform resource for nearby M dwarfs, and will be especially valuable for measuring Habitable Zone locations and comparative abundances of the M dwarf planet hosts that will be uncovered by upcoming exoplanet surveys.
