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1161. Hyperfine rotational transitions of 26Al19F
ID:
ivo://CDS.VizieR/J/other/NatAs/2.778
Title:
Hyperfine rotational transitions of 26Al19F
Short Name:
J/other/NatAs/2.
Date:
21 Oct 2021
Publisher:
CDS
Description:
Decades ago, {gamma}-ray observatories identified diffuse Galactic emission at 1.809MeV originating from {beta}^+^ decays of an isotope of aluminium, ^26^Al, that has a mean lifetime of 1.04 million years. Objects responsible for the production of this radioactive isotope have never been directly identified owing to insufficient angular resolutions and sensitivities of the {gamma}-ray observatories. Here, we report observations of millimetre-wave rotational lines of the isotopologue of aluminium monofluoride that contains the radioactive isotope (^26^AlF). The emission is observed towards CK Vul, which is thought to be a remnant of a stellar merger. Our constraints on the production of ^26^Al, combined with the estimates on the merger rate, make it unlikely that objects similar to CK Vul are major producers of Galactic ^26^Al. However, the observation may be a stepping stone for unambiguous identification of other Galactic sources of ^26^Al. Moreover, a high content of ^26^Al in the remnant indicates that, before the merger, the CK Vul system contained at least one solar-mass star that evolved to the red giant branch.
1162. IACOB Spectroscopic Database
ID:
ivo://iacvo/iacob
Title:
IACOB Spectroscopic Database
Short Name:
iacob
Date:
05 Feb 2024 17:22:56
Publisher:
Instituto de Astrofisica de Canarias (IAC) - Sergio Simon
Description:
OB-stars multi-epoch optical spectra from FIES@NOT and Hermes@Mecator at ORM/La Palma
1163. IC 4665
ID:
ivo://CDS.VizieR/J/AJ/105/1441
Title:
IC 4665
Short Name:
J/AJ/105/1441
Date:
21 Oct 2021
Publisher:
CDS
Description:
The results of a combined astrometric, photometric, and spectroscopic program to identify members of the open cluster IC 4665 are presented. Numerous new proper motion/photometric candidate members and at least 23 M dwarfs with H-alpha emission have been identified. A reanalysis of IC 4665's age using different methods yields conflicting results ranging from approx. 3x10^7^ yr to the age of the Pleiades. This study provides a list of candidate cluster members in the intermediate and low-mass regime of this cluster. Future spectroscopic observations of these candidates should eventually identify true cluster members. The results of new echelle observations of some candidates and the photometric monitoring of one apparent cluster member are given in an appendix.
1164. Identification of nitride dust
ID:
ivo://CDS.VizieR/J/MNRAS/371/1744
Title:
Identification of nitride dust
Short Name:
J/MNRAS/371/1744
Date:
21 Oct 2021
Publisher:
CDS
Description:
Nitride dust is predicted to form in small amounts around carbon stars, but the most likely candidate species such as aluminium nitride (AlN) have not yet been detected. Recently, {alpha}-Si_3_N_4_ was inferred to be the main carrier of the 8.5-12.5um absorption band(s) of an extreme carbon star (AFGL 5625), based on comparison with laboratory KBr dispersion spectra. However, this absorption band has also been attributed to silicon carbide (SiC) and C_3_. To investigate whether or not nitride dust has truly been detected and if it is present in other extreme carbon stars, we (i) gathered new laboratory infrared (IR) absorbance spectra from a suite of nitride compounds, including Si_3_N_4_, using the thin film technique which provides correct relative intensities of weak and strong peaks, and (ii) compared these data to Infrared Space Observatory Short Wavelength Spectrometer (ISO SWS) spectra of seven different extreme carbon stars which also show broad absorption features around ~11m.
1165. Identifying 3FHL. V. CTIO-COSMOS spectra
ID:
ivo://CDS.VizieR/J/ApJS/254/26
Title:
Identifying 3FHL. V. CTIO-COSMOS spectra
Short Name:
J/ApJS/254/26
Date:
19 Jan 2022 00:35:09
Publisher:
CDS
Description:
As a follow-up to the optical spectroscopic campaign aimed at achieving completeness in the Third Catalog of Hard Fermi-LAT Sources (3FHL), we present here the results of a sample of 28 blazars of an uncertain type observed using the 4m telescope at Cerro Tololo Inter-American Observatory in Chile. Out of these 28 sources, we find that 25 are BL Lacertae objects (BL Lacs) and 3 are flat-spectrum radio quasars (FSRQs). We measure redshifts or lower limits for 16 of these blazars, and it is observed that the 12 remaining blazars have featureless optical spectra. These results are part of a more extended optical spectroscopy follow-up campaign for 3FHL blazars, where, until now, 51 blazars of an uncertain type have been classified into BL Lac and FSRQ categories. Furthermore, this campaign has resulted in redshift measurements and lower limits for 15 of these sources. Our results contribute toward attaining a complete sample of blazars above 10 GeV, which then will be crucial in extending our knowledge on blazar emission mechanisms and the extragalactic background light.
1166. IFU observations of NGC 4191
ID:
ivo://CDS.VizieR/J/A+A/581/A65
Title:
IFU observations of NGC 4191
Short Name:
J/A+A/581/A65
Date:
21 Oct 2021
Publisher:
CDS
Description:
We here distinguish two counter-rotating stellar components in NGC 4191 and characterize their physical properties such as kinematics, size, morphology, age, metallicity. We obtained integral field spectroscopic observations with VIRUS-W and used a spectroscopic decomposition technique to separate the contribution of two stellar components to the observed galaxy spectrum. We also performed a photometric decomposition, modeling the galaxy with a Sersic bulge and two exponential disks of different scale length, with the aim of associating these structural components with the kinematic components. We then measured the equivalent width of the absorption line indices on the best-fit models that represent the kinematic components and compared our measurements to the predictions of stellar population models that also account for the variable abundance ratio of {alpha} elements.
1167. IGM absorbers toward HE 0226-4110
ID:
ivo://CDS.VizieR/J/ApJS/164/1
Title:
IGM absorbers toward HE 0226-4110
Short Name:
J/ApJS/164/1
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present an analysis of the FUSE (Far Ultraviolet Spectroscopic Explorer) and HST (Hubble Space Telescope) STIS E140M spectra of HE 0226-4110 (z=0.495). We detect 56 Lyman absorbers and five OVI absorbers.
1168. IGRINS spectral library
ID:
ivo://CDS.VizieR/J/ApJS/238/29
Title:
IGRINS spectral library
Short Name:
J/ApJS/238/29
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a library of high-resolution (R~45000) and high signal-to-noise ratio (S/N>=200) near-infrared spectra for stars of a wide range of spectral types and luminosity classes. The spectra were obtained with the Immersion GRating INfrared Spectrograph covering the full range of the H (1.496-1.780{mu}m) and K (2.080-2.460{mu}m) atmospheric windows. The targets were primarily selected for being MK standard stars covering a wide range of effective temperatures and surface gravities, with metallicities close to the solar value. Currently, the library includes flux-calibrated and telluric-absorption-corrected spectra of 84 stars, with prospects for expansion to provide denser coverage of the parametric space. Throughout the H and K atmospheric windows, we identified spectral lines that are sensitive to Teff or logg and defined corresponding spectral indices. We also provide their equivalent widths (EWs). For those indices, we derive empirical relations between the measured EWs and the stellar atmospheric parameters. Therefore, the derived empirical equations can be used to calculate the Teff and logg of a star without requiring stellar atmospheric models.
1169. IGR J19552+0044 BV light curves and spectra
ID:
ivo://CDS.VizieR/J/A+A/608/A36
Title:
IGR J19552+0044 BV light curves and spectra
Short Name:
J/A+A/608/A36
Date:
21 Oct 2021
Publisher:
CDS
Description:
Based on XMM-Newton X-ray observations IGR J19552+0044 appears to be either a pre-polar or an asynchronous polar. Aims. We conducted follow-up optical observations to identify the sources and periods of variability precisely and to classify this X-ray source correctly. Extensive multicolor photometric and medium- to high-resolution spectroscopy observations were performed and period search codes were applied to sort out the complex variability of the object. We found firm evidence of discording spectroscopic (81.29+/-0.01m) and photometric (83.599+/-0.002m) periods that we ascribe to the white dwarf (WD) spin period and binary orbital period, respectively. This confirms that IGR J19552+0044 is an asynchronous polar. Wavelength dependent variability and its continuously changing shape point at a cyclotron emission from a magnetic WD with a relatively low magnetic field below 20MG. The difference between the WD spin period and the binary orbital period proves that IGR J19552+0044 is a polar with the largest known degree of asynchronism (0.97 or 3%).
1170. II Pegasi spectra with PEPSI
ID:
ivo://CDS.VizieR/J/A+A/625/A27
Title:
II Pegasi spectra with PEPSI
Short Name:
J/A+A/625/A27
Date:
21 Oct 2021
Publisher:
CDS
Description:
We present a temperature and a magnetic-field surface map of the K2 subgiant of the active binary II Peg. Employed are high resolution Stokes IV spectra obtained with the new Potsdam Echelle Polarimetric and Spectroscopic Instrument (PEPSI) at the Large Binocular Telescope (LBT). Fourteen average line profiles are inverted using our iMap code. We have employed an iterative regularization scheme without the need of a penalty function and incorporate a physical 3D description of the surface field vector. The spectral resolution of our data is 130000 which converts to 20 resolution elements across the disk of II Peg. Our main result is that the temperature features on II Peg closely correlate with its magnetic field topology. We find a warm spot (350K warmer with respect to the effective temperature) of positive polarity and radial field density of 1.1kG coexisting with a cool spot (780K cooler) of negative polarity of 2kG. Several other cool features are reconstructed containing both polarities and with (radial) field densities of up to 2kG. The largest cool spot is reconstructed with a temperature contrast of 550K, an area of almost 10% of the visible hemisphere, and with a multipolar magnetic morphology. A meridional and an azimuthal component of the field of up to +/-500G is detected in two surface regions between spots with strong radial fields but different polarities. A force-free magnetic-field extrapolation suggests that the different polarities of cool spots and the positive polarity of warm spots are physically related through a system of coronal loops of typical height of ~=2R*. While the H{alpha} line core and its red-side wing exhibit variations throughout all rotational phases, a major increase of blue-shifted H{alpha} emission was seen for the phases when the warm spot is approaching the stellar central meridian indicating high-velocity mass motion within its loop. Active stars such as II Peg can show coexisting cool and warm spots on the surface that we interpret resulting from two different formation mechanisms. We explain the warm spots due to photospheric heating by a shock front from a siphon-type flow between regions of different polarities while the majority of the cool spots is likely formed due to the expected convective suppression like on the Sun.

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