- ID:
- ivo://CDS.VizieR/J/ApJ/868/133
- Title:
- j-M relation for disk and bulge type galaxies
- Short Name:
- J/ApJ/868/133
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We show that the stellar specific angular momentum j_*_, mass M_*_, and bulge fraction {beta}_*_ of normal galaxies of all morphological types are consistent with a simple model based on a linear superposition of independent disks and bulges. In this model, disks and bulges follow scaling relations of the form j_*_d{propto}M_*_d^{alpha}^ and j_*_b{propto}M_*_b^{alpha}^ with {alpha}=0.67+/-0.07 but offset from each other by a factor of 8+/-2 over the mass range 8.9<=log(M_*/M_{sun})<=11.8. Separate fits for disks and bulges alone give {alpha}=0.58+/-0.10 and {alpha}=0.83+/-0.16, respectively. This model correctly predicts that galaxies follow a curved 2D surface in the 3D space of log(j_*_), log(M_*_), and {beta}_*_. We find no statistically significant indication that galaxies with classical and pseudo bulges follow different relations in this space, although some differences are permitted within the observed scatter and the inherent uncertainties in decomposing galaxies into disks and bulges. As a byproduct of this analysis, we show that the j_*_-M_*_ scaling relations for disk-dominated galaxies from several previous studies are in excellent agreement with each other. In addition, we resolve some conflicting claims about the {beta}_*_ dependence of the j_*_-M_*_ scaling relations. The results presented here reinforce and extend our earlier suggestion that the distribution of galaxies with different {beta}_*_ in the j_*_-M_*_ diagram constitutes an objective, physically motivated alternative to subjective classification schemes such as the Hubble sequence.
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Search Results
- ID:
- ivo://CDS.VizieR/J/AJ/159/18
- Title:
- Jovian-type planets around M dwarfs with MIRI/JWST
- Short Name:
- J/AJ/159/18
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The upcoming launch of the James Webb Space Telescope (JWST) will dramatically increase our understanding of exoplanets, particularly through direct imaging. Microlensing and radial velocity surveys indicate that some M dwarfs host long-period giant planets. Some of these planets will likely be just a few parsecs away and a few astronomical units from their host stars, a parameter space that cannot be probed by existing high-contrast imagers. We studied whether the coronagraphs on the Mid-infrared Instrument on JWST can detect Jovian-type planets around nearby M dwarfs. For a sample of 27 very nearby M dwarfs, we simulated a sample of Saturn-Jupiter-mass planets with three atmospheric configurations and three orbital separations, observed in three different filters. We found that the f1550c 15.5 {mu}m filter is best suited for detecting Jupiter-like planets. Jupiter-like planets with patchy cloud cover, 2 au from their star, are detectable at 15.5 {mu}m around 14 stars in our sample, while Jupiters with clearer atmospheres are detectable around all stars in the sample. Saturns were most detectable at 10.65 and 11.4 {mu}m (f1065c and f1140c filters), but only with cloud-free atmospheres and within 3 pc (six stars). Surveying all 27 stars would take <170 hr of JWST integration time, or just a few hours for a shorter survey of the most favorable targets. There is one potentially detectable known planet in our sample: GJ 832 b. Observations aimed at detecting this planet should occur in 2024-2026, when the planet is maximally separated from the star.
- ID:
- ivo://CDS.VizieR/J/A+A/596/A114
- Title:
- Jupiter internal structure different EOS
- Short Name:
- J/A+A/596/A114
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Heavy elements, even though its smaller constituent, are crucial to understand Jupiter formation history. Interior models are used to determine the amount of heavy elements in Jupiter interior, nevertheless this range is still subject to degeneracies due to uncertainties in the equations of state. Prior to Juno mission data arrival, we present Jupiter optimized calculations exploring the ect of different model parameters in the determination of Jupiter's core and heavy element's mass. We perform comparisons between equations of state published recently. The interior model of Jupiter is calculated from the equations of hydrostatic equilibrium, mass and energy conservation, and energy transport. The mass of the core and heavy elements is adjusted to match Jupiter's observational constrains radius and gravitational moments
- ID:
- ivo://CDS.VizieR/J/ApJ/750/52
- Title:
- Jupiter model with improved EOS
- Short Name:
- J/ApJ/750/52
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The amount and distribution of heavy elements in Jupiter gives indications on the process of its formation and evolution. Core mass and metallicity predictions, however, depend on the equations of state (EOSs) used and on model assumptions. We present an improved ab initio hydrogen EOS, H-REOS.2, and compute the internal structure and thermal evolution of Jupiter within the standard three-layer approach. The advance over our previous Jupiter models with H-REOS.1 by Nettelmann et al. (2008ApJ...683.1217N) is that the new models are also consistent with the observed >~2 times solar heavy element abundances in Jupiter's atmosphere. Such models have a rock core mass M_c_=0-8M_{earth}_, total mass of heavy elements M_Z_=28-32M_{earth}_, a deep internal layer boundary at >=4Mbar, and a cooling time of 4.4-5.0Gyr when assuming homogeneous evolution. We also calculate two-layer models in the manner of Militzer et al. (2008ApJ...688L..45M) and find a comparable large core of 16-21M_{earth}_, out of which ~11M_{earth}_ is helium, but a significantly higher envelope metallicity of 4.5 times solar. According to our preferred three-layer models, neither the characteristic frequency ({nu}_0_~156{mu}Hz) nor the normalized moment of inertia ({lambda}~0.276) is sensitive to the core mass but accurate measurements could well help to rule out some classes of models.
- ID:
- ivo://CDS.VizieR/J/A+AS/122/399
- Title:
- K and evolutionary corrections
- Short Name:
- J/A+AS/122/399
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- K and evolutionary corrections are given for the E, Sa and Sc Hubble types for the following filters up to the redshift z=3: Johnson-Bessell & Brett photometric system: U, B, V, R, I, J, H, K filters Modified Thuan & Gunn system: gri filters Cousins system: Rc Ic filters Bj, Rf, In filters.
- ID:
- ivo://CDS.VizieR/J/AJ/140/390
- Title:
- Karhunen-Loeve transform of SDSS QSOs
- Short Name:
- J/AJ/140/390
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- The Karhunen-Loeve (KL) transform can compactly represent the information contained in large, complex datasets, cleanly eliminating noise from the data and identifying elements of the dataset with extreme or inconsistent characteristics. We develop techniques to apply the KL transform to the 4000-5700{AA} region of 9800 QSO spectra with z<0.619 from the SDSS archive. Up to 200 eigenspectra are needed to fully reconstruct the spectra in this sample to the limit of their signal-to-noise (S/N). We propose a simple formula for selecting the optimum number of eigenspectra to use to reconstruct any given spectrum, based on the S/N of the spectrum, but validated by formal cross-validation tests.
- ID:
- ivo://CDS.VizieR/J/A+A/658/A148
- Title:
- K corrections as a function of stellar param.
- Short Name:
- J/A+A/658/A148
- Date:
- 22 Feb 2022
- Publisher:
- CDS
- Description:
- Relativistic corrections are estimated for classical Cepheids and the Tip of the Red Giant Branch (TRGB stars), to enable future unbiased 1% measurements of Hubble's constant, H0. We considered four effects: K corrections, time-dilation, the apparent change of host dust extinction due to non-comoving reference frames, and the change of observed color due to redshift. Extinction-dependent K corrections were computed using stellar atmosphere models applicable to giant stars for 0.005<z<0.030 in HST, JWST, and 2MASS filters. The optical-NIR Wesenheit function advantageously combines filters with oppositely signed K-corrections and avoids complications due to host extinction. For TRGB stars, the JWST/NIRCAM F277W filter combines insensitivity to reddening with K corrections <1% at Coma cluster distances. Missing corrections for host extinction due to circumgalactic or circumstellar material are discussed as potential systematics for TRGB distances although their impacts are insufficient to explain differences between H0 based on Cepheid or TRGB supernova calibrations. All stellar standard candles require relativistic corrections to achieve an unbiased 1% H0 measurement in the future. The combined relativistic correction involving K, redshift-Leavitt bias, and the redshift-dependence of the Wesenheit function yield an increase of the Cepheid-based H0 by 0.45+/-0.05km/s/Mpc to 73.65+/-1.30km/s/Mpc and raises the tension with the Planck value from 4.2 to 4.4 sigma. For TRGB stars, we estimate a ~0.5% increase of H0 reported by Freedman et al. (to 70.2+/-1.7km/s/Mpc) and a small decrease by -0.15% for H0 reported by Anand et al. (to 71.4+/-1.8km/s/Mpc). The opposite sign of these corrections is due to different reddening systematics and reduces the difference between the studies by ~0.46km/s/Mpc. The optical-NIR Wesenheit function is particularly attractive for accurate distance measurements because it advantageously combines measurements in filters where K-corrections have opposite signs. The JWST/NIRCAM F277W filter is of particular interest for TRGB stars thanks to its insensitivity to (weak) host reddening and K-corrections below the level of 1% at Coma cluster distances.
- ID:
- ivo://CDS.VizieR/J/MNRAS/448/946
- Title:
- Kepler eclipse timing variation analyses
- Short Name:
- J/MNRAS/448/946
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- We report eclipse timing variation analyses of 26 compact hierarchical triple stars comprised of an eccentric eclipsing ("inner") binary and a relatively close tertiary component found in the Kepler field. We simultaneously fit the primary and secondary O-C curves of each system for the light-traveltime effect (LTTE), as well as dynamical perturbations caused by the tertiary on different time-scales. For the first time, we include those contributions of three-body interactions which originate from the eccentric nature of the inner binary. These effects manifest themselves both on the period of the triple system, P_2_, and on the longer "apse-node" time-scale. We demonstrate that consideration of the dynamically forced rapid apsidal motion yields an efficient and independent tool for the determination of the binary orbit's eccentricity and orientation, as well as the 3D configuration of the triple. Modelling the forced apsidal motion also helps to resolve the degeneracy between the shapes of the LTTE and the dynamical delay terms on the P_2_ time-scale, due to the strong dependence of the apsidal motion period on the triple's mass ratio. This can lead to the independent determination of the binary and tertiary masses without the need for independent radial velocity measurements. Through the use of our analytic method for fitting O-C curves, we have obtained robust solutions for system parameters for the 10 most ideal triples of our sample, and only somewhat less robust, but yet acceptable, fits for the remaining systems. Finally, we study the results of our 26 system parameter fits via a set of distributions of various physically important parameters, including mutual inclination angle, and mass and period ratios.
- ID:
- ivo://CDS.VizieR/J/ApJ/828/99
- Title:
- Kepler pipeline transit signal recovery. III.
- Short Name:
- J/ApJ/828/99
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- With each new version of the Kepler pipeline and resulting planet candidate catalog, an updated measurement of the underlying planet population can only be recovered with a corresponding measurement of the Kepler pipeline detection efficiency. Here we present measurements of the sensitivity of the pipeline (version 9.2) used to generate the Q1-Q17 DR24 planet candidate catalog. We measure this by injecting simulated transiting planets into the pixel-level data of 159013 targets across the entire Kepler focal plane, and examining the recovery rate. Unlike previous versions of the Kepler pipeline, we find a strong period dependence in the measured detection efficiency, with longer (>40 day) periods having a significantly lower detectability than shorter periods, introduced in part by an incorrectly implemented veto. Consequently, the sensitivity of the 9.2 pipeline cannot be cast as a simple one-dimensional function of the signal strength of the candidate planet signal, as was possible for previous versions of the pipeline. We report on the implications for occurrence rate calculations based on the Q1-Q17 DR24 planet candidate catalog, and offer important caveats and recommendations for performing such calculations. As before, we make available the entire table of injected planet parameters and whether they were recovered by the pipeline, enabling readers to derive the pipeline detection sensitivity in the planet and/or stellar parameter space of their choice.
- ID:
- ivo://CDS.VizieR/J/ApJ/880/L1
- Title:
- Kepler planet masses, radii and orbital periods
- Short Name:
- J/ApJ/880/L1
- Date:
- 21 Oct 2021
- Publisher:
- CDS
- Description:
- Structure in the planet distribution provides an insight into the processes that shape the formation and evolution of planets. The Kepler mission has led to an abundance of statistical discoveries in regards to planetary radius, but the number of observed planets with measured masses is much smaller. By incorporating results from recent mass determination programs, we have discovered a new gap emerging in the planet population for sub-Neptune-mass planets with orbital periods less than 20 days. The gap follows a slope of decreasing mass with increasing orbital period, has a width of a few M_{Earth}_, and is potentially completely devoid of planets. Fitting Gaussian mixture models to the planet population in this region favors a bimodel distribution over a unimodel one with a reduction in Bayesian information criterion of 19.9, highlighting the gap significance. We discuss several processes that could generate such a feature in the planet distribution, including a pileup of planets above the gap region, tidal interactions with the host star, dynamical interactions with the disk, with other planets, or with accreting material during the formation process.
