- ID:
- ivo://ov-gso/tsap/speconvol
- Title:
- Synthetic Spectra Convolution Service
- Short Name:
- speconvol
- Date:
- 03 Apr 2024 08:16:45
- Publisher:
- OV-GSO Virtual Observatory services
- Description:
- Convolution of normalized synthetic stellar spectra. Up to 3 successive convolutions are allowed on a adjustable portion of a synthetic spectrum, in order to mimic an observable. These convolutions acount for macroturbulence velocity, rotational velocity and instrumental profile. Finally, the output can be Doppler-shifted in order to take into account a stellar radial velocity.
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- ID:
- ivo://CDS.VizieR/J/A+A/659/A183
- Title:
- MUSE-Wide+MUSE-Deep EWs of Lyman{alpha} emitters
- Short Name:
- J/A+A/659/A183
- Date:
- 25 Mar 2022 09:08:03
- Publisher:
- CDS
- Description:
- The hydrogen Lyman{alpha} line is often the only measurable feature in optical spectra of high-redshift galaxies. Its shape and strength are influenced by radiative transfer processes and the properties of the underlying stellar population. High equivalent widths of several hundred {AA} are especially hard to explain by models and could point towards unusual stellar populations, for example with low metallicities, young stellar ages, and a top-heavy initial mass function. Other aspects influencing equivalent widths are the morphology of the galaxy and its gas properties. The aim of this study is to better understand the connection between the Lyman{alpha} rest-frame equivalent width (EW0) and spectral properties as well as ultraviolet (UV) continuum morphology by obtaining reliable EW0 histograms for a statistical sample of galaxies and by assessing the fraction of objects with large equivalent widths. We used integral field spectroscopy from the Multi Unit Spectroscopic Explorer (MUSE) combined with broad-band data from the Hubble Space Telescope (HST) to measure EW0 . We analysed the emission lines of 1920 Lyman{alpha} emitters (LAEs) detected in the full MUSE-Wide (one hour exposure time) and MUSE-Deep (ten hour exposure time) surveys and found UV continuum counterparts in archival HST data. We fitted the UV continuum photometric images using the Galfit software to gain morphological information on the rest-UV emission and fitted the spectra obtained from MUSE to determine the double peak fraction, asymmetry, full-width at half maximum, and flux of the Lyman{alpha} line. The two surveys show different histograms of Lyman{alpha} EW0 . In MUSE-Wide, 20% of objects have EW0>240{AA}, while this fraction is only 11% in MUSE-Deep and ~=16% for the full sample. This includes objects without HST continuum counterparts (one-third of our sample), for which we give lower limits for EW0. The object with the highest securely measured EW0 has EW0=589+/-193{AA} (the highest lower limit being EW0=4464{AA}). We investigate the connection between EW0 and Lyman{alpha} spectral or UV continuum morphological properties. The survey depth has to be taken into account when studying EW0 distributions. We find that in general, high EW0 objects can have a wide range of spectral and UV morphological properties, which might reflect that the underlying causes for high EW0 values are equally varied.
- ID:
- ivo://CDS.VizieR/J/A+A/588/A148
- Title:
- NGC 6397 stars MUSE spectra
- Short Name:
- J/A+A/588/A148
- Date:
- 23 Mar 2022 16:26:54
- Publisher:
- CDS
- Description:
- We demonstrate the high multiplex advantage of crowded field 3D spectroscopy with the new integral field spectrograph MUSE by means of a spectroscopic analysis of more than 12000 individual stars in the globular cluster NGC 6397. The stars are deblended with a point spread function fitting technique, using a photometric reference catalogue from HST as prior, including relative positions and brightnesses. This catalogue is also used for a first analysis of the extracted spectra, followed by an automatic in-depth analysis via a full-spectrum fitting method based on a large grid of PHOENIX spectra. We analysed the largest sample so far available for a single globular cluster of 18 932 spectra from 12 307 stars in NGC 6397. We derived a mean radial velocity of v_rad_=17.84+/-0.07km/s and a mean metallicity of [Fe/H]=-2.120+/-0.002, with the latter seemingly varying with temperature for stars on the red giant branch (RGB). We determine Teff and [Fe/H] from the spectra, and log g from HST photometry. This is the first very comprehensive Hertzsprung-Russell diagram (HRD) for a globular cluster based on the analysis of several thousands of stellar spectra, ranging from the main sequence to the tip of the RGB. Furthermore, two interesting objects were identified; one is a post-AGB star and the other is a possible millisecond-pulsar companion.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A125
- Title:
- KI diagnostic capabilities for M dwarfs
- Short Name:
- J/A+A/657/A125
- Date:
- 21 Mar 2022 09:37:41
- Publisher:
- CDS
- Description:
- The strong KI doublet near 7700{AA} and another doublet near 12500{AA} are studied in a sample of 324 M dwarfs using CARMENES spectra. For the optical doublet we use only the red line, since the blue line is often contaminated by telluric correction artefacts. Both doublets have a dominant photospheric component in inactive stars and can be used as tracers of effective temperature and gravity. For M dwarfs later than M5.0V the optical doublet lines develop an emission core. The line is often correlated to H{alpha} for stars with H{alpha} in emission and anticorrelated for stars with H{alpha} in absorption. The near-infrared doublet lines very rarely show correlation/anti-correlation to H{alpha}.
- ID:
- ivo://CDS.VizieR/J/ApJ/900/104
- Title:
- IR high-res. sp. of hot cores of AFGL2591 & AFGL2136
- Short Name:
- J/ApJ/900/104
- Date:
- 21 Mar 2022 09:36:08
- Publisher:
- CDS
- Description:
- We have performed a high-resolution 4-13{mu}m spectral survey of the hot molecular gas associated with the massive protostars AFGL 2591 and AFGL 2136, utilizing the Echelon Cross Echelle Spectrograph (EXES) on board the Stratospheric Observatory for Infrared Astronomy, and the iSHELL instrument and Texas EchelonCross Echelle Spectrograph (TEXES) on the NASA Infrared Telescope Facility (IRTF). Here we present the results of this survey with analysis of CO, HCN, C2H2, NH3, and CS, deriving the physical conditions for each species. Also from the IRTF, iSHELL data at 3{mu}m for AFGL 2591 are presented that show HCN and C2H2 in emission. In the EXES and TEXES data, all species are detected in absorption, and temperatures and abundances are found to be high (600K and 10^-6^, respectively). Differences of up to an order of magnitude in the abundances of transitions that trace the same ground-state level are measured for HCN and C2H2. The mid-infrared continuum is known to originate in a disk, hence we attribute the infrared absorption to arise in the photosphere of the disk. As absorption lines require an outwardly decreasing temperature gradient, we conclude that the disk is heated in the midplane by viscous heating due to accretion. We attribute the near-IR emission lines to scattering by molecules in the upper layers of the disk photosphere. The absorption lines trace the disk properties at 50 au where high-temperature gas-phase chemistry is taking place. Abundances are consistent with chemical models of the inner disk of Herbig disks.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A99
- Title:
- The rotational spectrum of glycinamide
- Short Name:
- J/A+A/657/A99
- Date:
- 21 Mar 2022 09:35:44
- Publisher:
- CDS
- Description:
- Glycinamide (NH_2_CH_2_C(O)NH_2_) is considered to be one of the possible precursors of the simplest amino acid glycine. Its only rotational spectrum reported so far has been in the cm-wave region on a laser-ablation generated supersonic expansion sample. The aim of this work is to extend the laboratory spectrum of glycinamide into the millimetre wave region to support its searches in the interstellar medium and to perform the first check for its presence in the high-mass star forming region Sagittarius B2(N). Glycinamide was synthesised chemically and was studied with broadband rotational spectroscopy in the 90-329 GHz region with the sample in slow flow at 50{deg}C. Tunneling across a low energy barrier between two symmetry equivalent configurations of the molecule resulted in splitting of each vibrational state and many perturbations in associated rotational energy levels, requiring careful coupled state fits for each vibrational doublet. We searched for emission of glycinamide in the imaging spectral line survey ReMoCA performed with the Atacama Large Millimetre/submillimetre Array toward Sgr B2(N). The astronomical spectra were analysed under the assumption of local thermodynamic equilibrium. We report the first analysis of the mm-wave rotational spectrum of glycinamide, resulting in fitting to experimental measurement accuracy of over 1200 assigned and measured transition frequencies for the ground state tunneling doublet, of many lines for tunneling doublets for two singly excited vibrational states, and determination of precise vibrational separation in each doublet. We did not detect emission from glycinamide in the hot molecular core Sgr B2(N1S). We derived a column density upper limit of 1.5x10^16^cm^-2^, which implies that glycinamide is at least seven times less abundant than aminoacetonitrile and 1.8 times less abundant than urea in this source.
- ID:
- ivo://CDS.VizieR/J/ApJ/900/47
- Title:
- UV to NIR spectra of the QSO 2MASS J15165323+1900482
- Short Name:
- J/ApJ/900/47
- Date:
- 21 Mar 2022 09:27:00
- Publisher:
- CDS
- Description:
- We present detailed studies of the partially obscured quasar 2MASSJ151653.23+190048.2 with continuous broadband spectrophotometry from near-infrared (NIR) through optical to ultraviolet (UV). The NIR and optical spectra show strong broad emission lines, while the UV spectrum is dominated by a set of rich intermediate-width emission lines (IELs). These IELs, unshifted with respect to the quasar systemic velocity measured by narrow emission lines, share a common profile of about 1900km/s in FWHM, in contrast to the Balmer and Paschen broad emission lines of FWHM ~6300km/s observed in the optical and NIR. The intermediate width of these lines indicates that the emitting gas may come from the dusty torus region. However, the observed peculiar IEL intensity ratios, such as NV{lambda}1240/Ly{alpha}, indicate that the emitting gas has a very high density, up to ~10^13^cm^-3^. Such a high density is unusual for gas around the dusty torus region, except that we consider mechanisms such as shocks that can produce local ultradense gas. We speculate that these emission lines could originate from the shock region, possibly induced by the quasar outflow colliding with the inner wall of the dusty torus. If true, this may give us an opportunity to peep at the quasar outflows at the scale of the dusty torus that have so far been elusive due to the limited resolving powers of existing facilities.
- ID:
- ivo://CDS.VizieR/J/ApJ/900/42
- Title:
- CARMENES obs. of the binary system LB-1
- Short Name:
- J/ApJ/900/42
- Date:
- 21 Mar 2022 09:26:37
- Publisher:
- CDS
- Description:
- The mass, origin, and evolutionary stage of the binary system LB-1 have been intensely debated, following the claim that it hosts an ~70M_{sun}_ black hole, in stark contrast with the expectations for Galactic remnants. We conducted a high-resolution, phase-resolved spectroscopic study of its Paschen lines, using the Calar Alto 3.5m telescope. We find that Pa{beta} and Pa{gamma} (after subtraction of the stellar absorption component) are well fitted with a standard double-peaked disk profile. We measured the velocity shifts of the red and blue peaks at 28 orbital phases: the line center has an orbital motion in perfect antiphase with the secondary, and the radial velocity amplitude ranges from 8 to 13km/s, for different methods of profile modeling. We interpret this curve as proof that the disk traces the orbital motion of the primary, ruling out the circumbinary disk and the hierarchical triple scenarios. The phase-averaged peak-to-peak half-separation (a proxy for the projected rotational velocity of the outer part of the disk) is ~70km/s, larger than the orbital velocity of the secondary and inconsistent with a circumbinary disk. From those results, we infer a primary mass 4-8 times higher than the secondary mass. Moreover, we show that the intensity ratio of the blue and red peaks has a sinusoidal behavior in phase with the secondary, which we attribute to external irradiation of the outer part of the disk. Finally, we discuss our findings in the context of competing scenarios proposed for LB-1. Further astrometric Gaia data will test between alternative solutions.
- ID:
- ivo://CDS.VizieR/J/A+A/657/A17
- Title:
- Gaia 19bld spectroscopic follow-up
- Short Name:
- J/A+A/657/A17
- Date:
- 21 Mar 2022 09:21:49
- Publisher:
- CDS
- Description:
- As the event displayed an increased brightness, spectroscopic follow-up observations were immediately scheduled. Low-resolution spectra (R~500) were obtained using the FLOYDS spectrograph, which is mounted on the Las Cumbres Observatory (LCO) 2-m telescope at Siding Spring Observatory In addition,we used the X-shooter instrument mounted on the ESO Very Large Telescope (VLT) which is a multi-wavelength, medium-resolution spectrograph consisted of three spectroscopic arms allowing for simultaneous observations at three wavelength ranges: UVB (300-559.5nm), VIS (559.5-1024nm), and NIR (1024-2480nm). Spectra used in this publication.
- ID:
- ivo://CDS.VizieR/J/ApJ/898/166
- Title:
- UV to NIR obs. of SN 2019ehk
- Short Name:
- J/ApJ/898/166
- Date:
- 21 Mar 2022 09:18:33
- Publisher:
- CDS
- Description:
- We present panchromatic observations and modeling of the Calcium-rich supernova (SN) 2019ehk in the star-forming galaxy M100 (d~16.2Mpc) starting 10hr after explosion and continuing for ~300days. SN 2019ehk shows a double-peaked optical light curve peaking at t=3 and 15days. The first peak is coincident with luminous, rapidly decaying Swift-XRT-discovered X-ray emission (L_x_~10^41^erg/s at 3days; Lx{propto}t^-3^), and a Shane/Kast spectral detection of narrow H{alpha} and HeII emission lines (v~500km/s) originating from pre-existent circumstellar material (CSM). We attribute this phenomenology to radiation from shock interaction with extended, dense material surrounding the progenitor star at r<10^15^cm and the resulting cooling emission. We calculate a total CSM mass of ~7x10^-3^M_{sun}_ (M_He_/M_H_~6) with particle density n~10^9^cm^-3^. Radio observations indicate a significantly lower density n<10^4^cm^-3^ at larger radii r>(0.1-1)x10^17^cm. The photometric and spectroscopic properties during the second light-curve peak are consistent with those of Ca-rich transients (rise-time of t_r_=13.4!+/-0.210days and a peak B-band magnitude of M_B_=-15.1+/-0.200mag). We find that SN 2019ehk synthesized (3.1+/-0.11)x10^-2^M_{sun}_ of ^56^Ni and ejected M_ej_=(0.72+/-0.040)M_{sun}_ total with a kinetic energy E_k_=(1.8+/-0.10)x10^50^erg. Finally, deep HST pre-explosion imaging at the SN site constrains the parameter space of viable stellar progenitors to massive stars in the lowest mass bin (~10M_{sun}_) in binaries that lost most of their He envelope or white dwarfs (WDs). The explosion and environment properties of SN 2019ehk further restrict the potential WD progenitor systems to low-mass hybrid HeCO WD+CO WD binaries.