- ID:
- ivo://CDS.VizieR/J/ApJ/741/32
- Title:
- Spatial extent of (U)LIRGs in the MIR. II.
- Short Name:
- J/ApJ/741/32
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present results from the second part of our analysis of the extended mid-infrared (MIR) emission of the GOALS sample based on 5-14um low-resolution spectra obtained with the Infrared Spectrograph on Spitzer. We calculate the fraction of extended emission (FEE) as a function of wavelength for all galaxies in the sample, FEE_{lambda}_, defined as the fraction of the emission that originates outside of the unresolved central component of a source, and spatially separate the MIR spectrum of a galaxy into its nuclear and extended components. We find that the [NeII]12.81um emission line is as compact as the hot dust MIR continuum, while the polycyclic aromatic hydrocarbon (PAH) emission is more extended. In addition, the 6.2 and 7.7um PAH emission is more compact than that of the 11.3um PAH, which is consistent with the formers being enhanced in a more ionized medium. The presence of an active galactic nucleus (AGN) or a powerful nuclear starburst increases the compactness and the luminosity surface density of the hot dust MIR continuum, but has a negligible effect on the spatial extent of the PAH emission on kpc-scales. Furthermore, it appears that both processes, AGN and/or nuclear starburst, are indistinguishable in terms of how they modify the integrated PAH-to-continuum ratio of the FEE in (ultra)luminous infrared galaxies ((U)LIRGs). Globally, the 5-14um spectra of the extended emission component are homogeneous for all galaxies in the GOALS sample.
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Search Results
- ID:
- ivo://CDS.VizieR/J/MNRAS/422/3370
- Title:
- Spatial variation in fine-structure constant
- Short Name:
- J/MNRAS/422/3370
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Quasar absorption lines provide a precise test of whether the fine-structure constant, {alpha}, is the same in different places and through cosmological time. We present a new analysis of a large sample of quasar absorption-line spectra obtained using the Ultraviolet and Visual Echelle Spectrograph (UVES) on the Very Large Telescope (VLT) in Chile. We apply the many-multiplet method to derive values of {DELTA}{alpha}/{alpha}==({alpha}z-{alpha}0)/{alpha}0 from 154 absorbers, and combine these values with 141 values from previous observations at the Keck Observatory in Hawaii.
- ID:
- ivo://CDS.VizieR/J/AJ/126/2963
- Title:
- Spatiokinematics of NGC 1514
- Short Name:
- J/AJ/126/2963
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- New spatiokinematic observations were undertaken of the planetary nebula NGC 1514 in the [O III] line at 5007{AA} using an imaging Fabry-Perot spectrometer. Our results show an inner ellipsoidal shell and polar blobs that do not conform to bipolar morphology. It is argued that the nebula is a descendant of a common envelope binary system the periodicity of which is estimated to be about 10 days, with a progenitor mass of 4.5M_{sun}_.
- ID:
- ivo://CDS.VizieR/J/A+A/570/A2
- Title:
- Spectra and radial velocities of nuclear stars
- Short Name:
- J/A+A/570/A2
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Within the central 10pc of our Galaxy lies a dense cluster of stars. This nuclear star cluster forms a distinct component of the Galaxy, and similar nuclear star clusters are found in most nearby spiral and elliptical galaxies. Studying the structure and kinematics of nuclear star clusters reveals the history of mass accretion and growth of galaxy nuclei and central massive black holes. Because the Milky Way nuclear star cluster is at a distance of only 8 kpc, we can spatially resolve the cluster on sub-parsec scales. This makes the Milky Way nuclear star cluster a reference object for understanding the formation of all nuclear star clusters.
- ID:
- ivo://CDS.VizieR/J/ApJS/151/299
- Title:
- Spectra classification from ISO PHT-S database
- Short Name:
- J/ApJS/151/299
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have classified over 1500 infrared spectra obtained with the PHT-S spectrometer aboard the Infrared Space Observatory according to the system developed for the Short Wavelength Spectrometer (SWS) spectra by Kraemer et al. (2002ApJS..140..389K). The majority of these spectra contribute to subclasses that are either under-represented in the SWS spectral database or contain sources that are too faint, such as M dwarfs, to have been observed by either the SWS or the Infrared Astronomical Satellite Low Resolution Spectrometer. There is strong overall agreement about the chemistry of objects observed with both instruments. Discrepancies can usually be traced to the different wavelength ranges and sensitivities of the instruments. Finally, a large subset of the observations (~250 spectra) exhibit a featureless, red continuum that is consistent with emission from zodiacal dust and suggest directions for further analysis of this serendipitous measurement of the zodiacal background.
- ID:
- ivo://CDS.VizieR/J/ApJ/884/L31
- Title:
- Spectra & HST obs. of gal. in 1ES1553+113 field
- Short Name:
- J/ApJ/884/L31
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The relationship between galaxies and the state/chemical enrichment of the warm-hot intergalactic medium (WHIM) expected to dominate the baryon budget at low-z provides sensitive constraints on structure formation and galaxy evolution models. We present a deep redshift survey in the field of 1ES1553+113, a blazar with a unique combination of ultraviolet (UV)+X-ray spectra for surveys of the circumgalactic/intergalactic medium (CGM/IGM). Nicastro+ (2018Natur.558..406N) reported the detection of two OVII WHIM absorbers at z=0.4339 and 0.3551 in its spectrum, suggesting that the WHIM is metal rich and sufficient to close the missing baryons problem. Our survey indicates that the blazar is a member of a z=0.433 group and that the higher-z OVII candidate arises from its intragroup medium. The resulting bias precludes its use in baryon censuses. The z=0.3551 candidate occurs in an isolated environment 630kpc from the nearest galaxy (with stellar mass logM_*_/M_{sun}_~9.7), which we show is unexpected for the WHIM. Finally, we characterize the galactic environments of broad HI Ly{alpha} absorbers (Doppler widths of b=40-80km/s; T<~4x10^5^K) that provide metallicity-independent WHIM probes. On average, broad Ly{alpha} absorbers are ~2x closer to the nearest luminous (L>0.25L*) galaxy (700kpc) than narrow (b<30km/s; T<~4x10^5^K) ones (1300kpc) but ~2x further than OVI absorbers (350kpc). These observations suggest that gravitational collapse heats portions of the IGM to form the WHIM, but with feedback that does not enrich the IGM far beyond galaxy/group halos to levels currently observable in UV/X-ray metal lines.
- ID:
- ivo://CDS.VizieR/J/ApJ/771/114
- Title:
- Spectral analysis of 100 evolved PNe from SPM
- Short Name:
- J/ApJ/771/114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have selected a group of 100 evolved planetary nebulae (PNe) and study their kinematics based upon spatially-resolved, long-slit, echelle spectroscopy. The data have been drawn from the San Pedro Martir Kinematic Catalogue of PNe (SPM Catalogue). The aim is to characterize in detail the global kinematics of PNe at advanced stages of evolution with the largest sample of homogenous data used to date for this purpose. The results reveal two groups that share kinematics, morphology, and photo-ionization characteristics of the nebular shell and central star luminosities at the different late stages under study. The typical flow velocities we measure are usually larger than seen in earlier evolutionary stages, with the largest velocities occurring in objects with very weak or absent [NII]{lambda}6584 line emission, by all indications the least evolved objects in our sample. The most evolved objects expand more slowly. This apparent deceleration during the final stage of PNe evolution is predicted by hydrodynamical models, but other explanations are also possible. These results provide a template for comparison with the predictions of theoretical models.
- ID:
- ivo://CDS.VizieR/J/ApJ/711/138
- Title:
- Spectral analysis of HIP 60350 and 18 Peg
- Short Name:
- J/ApJ/711/138
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Young, massive stars in the Galactic halo are widely supposed to be the result of an ejection event from the Galactic disk forcing some stars to leave their place of birth as so-called runaway stars. Here, we present a detailed spectroscopic and kinematic analysis of the runaway B star HIP 60350 to determine which runaway scenario -a supernova explosion disrupting a binary system or dynamical interaction in star clusters- may be responsible for HIP 60350's peculiar orbit. Based on a non-local thermodynamic equilibrium approach, a high-resolution optical echelle spectrum was examined to revise spectroscopic quantities and for the first time to perform a differential chemical abundance analysis with respect to the B-type star 18 Peg. The results together with proper motions from the Hipparcos Catalog further allowed the three-dimensional kinematics of the star to be studied numerically. The abundances derived for HIP 60350 are consistent with a slightly supersolar metallicity agreeing with the kinematically predicted place of birth ~6kpc away from the Galactic center. However, they do not exclude the possibility of an {alpha}-enhanced abundance pattern expected in the case of the supernova scenario. Its outstanding high Galactic rest-frame velocity of 530+/-35km/s is a consequence of ejection in the direction of Galactic rotation and slightly exceeds the local Galactic escape velocity in a standard Galactic potential. Hence, HIP 60350 may be unbound to the Galaxy.
- ID:
- ivo://CDS.VizieR/J/A+A/542/A56
- Title:
- Spectral analysis of 2010-11 outburst of GX 339-4
- Short Name:
- J/A+A/542/A56
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Galactic transient black hole candidate (BHC) GX 339-4 exhibited several outbursts at regular intervals of about two to three years in the Rossi X-ray Timing Explorer (RXTE) era. After remaining in an almost quiescent state for three long years, it again became X-ray active in January, 2010, continuing to be so over the next ~14 months. We study the timing and spectral properties of the BHC during its recent outburst and understand the behavioral change in the accretion flow dynamics associated with the evolution of the various X-ray features. The detailed analysis of the temporal and spectral properties of the source during this outburst are carried out using archival data of the RXTE PCA instrument. We analyze a total of 236 observational intervals consisting of 419 days of data observed by RXTE, from 2010 January 12 to 2011 March 6.
- ID:
- ivo://CDS.VizieR/J/AZh/81/333
- Title:
- Spectral analysis of V510 Pup
- Short Name:
- J/AZh/81/333
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have carried out a detailed identification of lines in the optical spectrum of the post-AGB star V510Pup associated with the infrared source IRAS08005-2356. Absorbtion lines of the ions FeII, TiII, CrII, YII are presented at wavelengths from 4549 to 8546 A. The absorptions YII and other s-process elements are anomalously strong. There is also strong in the circumstellar C_2_ Swan bands. The profiles of most of the lines (of hydrogen and metals) display absorption-emission P Cyg type profiles. All the absorption lines are shifted toward shorter wavelengths, suggesting an outflow of stellar material. The expansion velocity of the envelope derived from the Swan bands arising there is Vexp=42km/s. The highest wind velocity determined from the absorptional wings of FeII(42) P Cygni profiles reachs 240km/s. Based on the star's kinematic characteristics and the amount of interstellar absorption, the distance to this object is d~3-4kpc.
