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- ID:
- ivo://CDS.VizieR/J/MNRAS/412/1419
- Title:
- Nearby supernova rates
- Short Name:
- J/MNRAS/412/1419
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- This is the first paper of a series in which we present new measurements of the observed rates of supernovae (SNe) in the local Universe, determined from the Lick Observatory Supernova Search. We have obtained 2.3 million observations of 14 882 sample galaxies over an interval of 11 years (1998 March to 2008 December). We considered 1036 SNe detected in our sample and used an optimal subsample of 726 SNe (274 Type Ia SNe, 116 Type Ibc SNe and Type II 324 SNe) to determine our SN rates. This is the largest and most homogeneous set of nearby SNe ever assembled for this purpose, and ours is the first local SN rate analysis based on CCD imaging and modern image-subtraction techniques. In this paper, we lay the foundation of the study.
- ID:
- ivo://CDS.VizieR/J/AJ/154/168
- Title:
- NEOWISE: thermal model fits for NEOs and MBAs
- Short Name:
- J/AJ/154/168
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Near-Earth ObjectWide-field Infrared Survey Explorer (NEOWISE) reactivation mission has completed its third year of surveying the sky in the thermal infrared for near-Earth asteroids and comets. NEOWISE collects simultaneous observations at 3.4 and 4.6 {mu}m of solar system objects passing through its field of regard. These data allow for the determination of total thermal emission from bodies in the inner solar system, and thus the sizes of these objects. In this paper, we present thermal model fits of asteroid diameters for 170 NEOs and 6110 Main Belt asteroids (MBAs) detected during the third year of the survey, as well as the associated optical geometric albedos. We compare our results with previous thermal model results from NEOWISE for overlapping sample sets, as well as diameters determined through other independent methods, and find that our diameter measurements for NEOs agree to within 26% (1{sigma}) of previously measured values. Diameters for the MBAs are within 17% (1{sigma}). This brings the total number of unique near-Earth objects characterized by the NEOWISE survey to 541, surpassing the number observed during the fully cryogenic mission in 2010.
- ID:
- ivo://CDS.VizieR/J/A+A/446/97
- Title:
- NEP Distant Cluster Radio Galaxies
- Short Name:
- J/A+A/446/97
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- A complete sample of 18 X-ray selected clusters of galaxies belonging to the ROSAT North Ecliptic Pole (NEP) survey has been observed with the Very Large Array at 1.4GHz in B configuration. These are the most distant clusters in the X-ray survey with redshift in the range 0.3<z<0.8. Seventy-nine radio sources are detected within half an Abell radius with an observed peak brightness >=0.17mJy/beam, except for three sources, belonging to the same cluster, which have a higher peak brightness limit of 0.26mJy/beam. The NEP field source counts are in good agreement with the source counts of a comparison survey, the VLA-VIRMOS deep field survey, indicating that the NEP sample is statistically complete. Thirty-two out of the 79 sources are within 0.2 Abell radii, twenty-two of them are considered cluster members based on spectroscopic redshifts or their optical magnitude and morphological classification. The cluster radio galaxies are used to construct the Radio Luminosity Function (RLF) of distant X-ray selected clusters. A comparison with two nearby cluster RLFs shows that the NEP RLF lies above the local ones, has a steeper slope at low radio powers (<=10^24^W/Hz) and shows no evidence for a break at about 6x10^24^W/Hz which is observed in the nearby cluster RLFs. We discuss briefly the origin and possible explanations of the differences observed in the radio properties of nearby and distant clusters of galaxies. The main result of this study is that the RLF of the distant X-ray clusters is very different from that of the local rich Abell clusters.
- ID:
- ivo://CDS.VizieR/J/MNRAS/466/1868
- Title:
- Neptune-like planets low-density overabundance
- Short Name:
- J/MNRAS/466/1868
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a uniform analysis of the atmospheric escape rate of Neptune-like planets with estimated radius and mass (restricted to M_p_<30M_{Earth}_). For each planet, we compute the restricted Jeans escape parameter, {Lambda}, for a hydrogen atom evaluated at the planetary mass, radius, and equilibrium temperature. Values of {Lambda}<=20 suggest extremely high mass-loss rates. We identify 27 planets (out of 167) that are simultaneously consistent with hydrogen-dominated atmospheres and are expected to exhibit extreme mass-loss rates. We further estimate the mass-loss rates (L_hy_) of these planets with tailored atmospheric hydrodynamic models. We compare L_hy_ to the energy-limited (maximum-possible high-energy driven) mass-loss rates. We confirm that 25 planets (15 per cent of the sample) exhibit extremely high mass-loss rates (L_hy_>0.1M_{Earth}_/Gyr), well in excess of the energy-limited mass-loss rates. This constitutes a contradiction, since the hydrogen envelopes cannot be retained given the high mass-loss rates. We hypothesize that these planets are not truly under such high mass-loss rates. Instead, either hydrodynamic models overestimate the mass-loss rates, transit-timing-variation measurements underestimate the planetary masses, optical transit observations overestimate the planetary radii (due to high-altitude clouds), or Neptunes have consistently higher albedos than Jupiter planets. We conclude that at least one of these established estimations/techniques is consistently producing biased values for Neptune planets. Such an important fraction of exoplanets with misinterpreted parameters can significantly bias our view of populations studies, like the observed mass-radius distribution of exoplanets for example.
- ID:
- ivo://CDS.VizieR/J/MNRAS/469/2539
- Title:
- New classification of CALIFA galaxies
- Short Name:
- J/MNRAS/469/2539
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We present a galaxy classification system for 238 (E1-Sdm) CALIFA (Calar Alto Legacy Integral Field Area) galaxies based on the shapes and amplitudes of their circular velocity curves (CVCs). We infer the CVCs from the de-projected surface brightness of the galaxies, after scaling by a constant mass-to-light ratio based on stellar dynamics - solving axisymmetric Jeans equations via fitting the second velocity moment V_rms_=sqrt{V^2^+{sigma}^2^} of the stellar kinematics. We use principal component analysis (PCA) applied to the CVC shapes to find characteristic features and use a k-means classifier to separate circular curves into classes. This objective classification method identifies four different classes, which we name slow-rising (SR), flat (FL), round-peaked (RP) and sharp-peaked (SP) circular curves. SR are typical for low-mass, late-type (Sb-Sdm), young, faint, metal-poor and disc-dominated galaxies. SP are typical for high-mass, early-type (E1-E7), old, bright, metal-rich and bulge-dominated galaxies. FL and RP appear presented by galaxies with intermediate mass, age, luminosity, metallicity, bulge-to-disc ratio and morphologies (E4-S0a, Sa-Sbc). The discrepancy mass factor, f_d_=1-M_*_/M_dyn_, have the largest value for SR and SP classes (~74 per cent and ~71 per cent, respectively) in contrast to the FL and RP classes (with ~59 per cent and ~61 per cent, respectively). Circular curve classification presents an alternative to typical morphological classification and appears more tightly linked to galaxy evolution.
- ID:
- ivo://CDS.VizieR/J/AJ/141/134
- Title:
- New classification of young planetary nebulae
- Short Name:
- J/AJ/141/134
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Using Hubble Space Telescope images of 119 young planetary nebulae (PNs), most of which have not previously been published, we have devised a comprehensive morphological classification system for these objects. This system generalizes a recently devised system for pre-planetary nebulae, which are the immediate progenitors of PNs. Unlike previous classification studies, we have focused primarily on young PNs rather than all PNs, because the former best show the influences or symmetries imposed on them by the dominant physical processes operating at the first and primary stage of the shaping process. Older PNs develop instabilities, interact with the ambient interstellar medium, and are subject to the passage of photoionization fronts, all of which obscure the underlying symmetries and geometries imposed early on. Our classification system is designed to suffer minimal prejudice regarding the underlying physical causes of the different shapes and structures seen in our PN sample, however, in many cases, physical causes are readily suggested by the geometry, along with the kinematics that have been measured in some systems. Secondary characteristics in our system, such as ansae, indicate the impact of a jet upon a slower-moving, prior wind; a waist is the signature of a strong equatorial concentration of matter, whether it be outflowing or in a bound Keplerian disk, and point symmetry indicates a secular trend, presumably precession, in the orientation of the central driver of a rapid, collimated outflow.
- ID:
- ivo://CDS.VizieR/J/PAZh/33/577
- Title:
- New dwarf galaxies in northern groups
- Short Name:
- J/PAZh/33/577
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We have searched for nearby dwarf galaxies in 27 northern groups with characteristic distances 8-15Mpc based on the Second Palomar Sky Survey prints. In a total area of about 2000 square degrees, we have found 90 low-surface-brightness objects, more than 60% of which are absent from known catalogs and lists. We have classified most of these objects (80%) as irregular dwarf systems. The first 21-cm line observations of the new objects with the 100-m Effelsberg radio telescope showed that the typical linear diameters (1-2kpc), internal motions (30km/s), and hydrogen masses (2x10^7^M_{sun}_) of the new galaxies correspond to those expected for the dwarf population of nearby groups.
- ID:
- ivo://CDS.VizieR/J/A+A/373/536
- Title:
- New galactic bulge PNe
- Short Name:
- J/A+A/373/536
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We observed 64 newly identified galactic bulge planetary nebulae in the radio continuum at 3 and 6 cm with the Australia Telescope Compact Array. We present their radio images, positions, flux densities, and angular sizes. The survey appears to have detected a larger ratio of more extended planetary nebulae with low surface brightness than in previous surveys. We calculated their distances according to Van de Steene & Zijlstra (1995A&A...293..541V). We find that most of the new sample is located on the near side around the galactic center and closer in than the previously known bulge PNe. Based on H{alpha} images and spectroscopic data, we calculated the total H{alpha} flux. We compare this flux value with the radio flux density and derive the extinction. We confirm that the distribution of the extinction values around the galactic center rises toward the center, as expected.
- ID:
- ivo://CDS.VizieR/J/other/NewA/34.84
- Title:
- New Galactic embedded cluster candidates
- Short Name:
- J/other/NewA/34.
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We carried out a search for new infrared star clusters, stellar groups and candidates using WISE images, which are very sensitive to dust emission nebulae. We report the discovery of 437 embedded clusters and stellar groups that show a variety of structures, both in the stellar and nebular components. Pairs or small groupings of clusters are observed, suggesting multiple generations at the early formation stages. The resulting catalogue provides Galactic and equatorial coordinates, together with angular sizes for all objects. The nature of a representative test sub-sample of 14 clusters is investigated in detail by means of 2MASS photometry. The colour magnitude diagrams and radial density distributions characterise them as stellar clusters. The 437 new objects were found in the ranges 145{deg}<.l<=290{deg} and -25{deg}<=b<=20{deg}, and they appear to be a major object source for future studies of star cluster formation and their early evolution. WISE is a powerful tool to further probe for very young clusters throughout the disk.
