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We present a mid-infrared Tully-Fisher (TF) relation using photometry from the 3.4-micron W1 band of the Wide-field Infrared Survey Explorer (WISE) satellite. The WISE TF relation is formed from 568 galaxies taken from the all-sky 2MASS Tully-Fisher (2MTF) galaxy catalog, spanning a range of environments including field, group, and cluster galaxies. This constitutes the largest mid-infrared TF relation constructed, to date. After applying a number of corrections to galaxy magnitudes and line widths, we measure a master TF relation given by M_corr = -22.24 - 10.05[log(W_corr) - 2.5], with an average dispersion of sigma_WISE = 0.686 magnitudes. There is some tension between WISE TF and a preliminary 3.6-micron relation, which has a shallower slope and almost no intrinsic dispersion. However, our results agree well with a more recent relation constructed from a large sample of cluster galaxies. We additionally compare WISE TF to the near-infrared 2MTF template relations, finding a good agreement between the TF parameters and total dispersions of WISE TF and the 2MTF K-band template. This fact, coupled with typical galaxy colors of (K - W1) ~ 0, suggests that these two bands are tracing similar stellar populations, including the older, centrally-located stars in the galactic bulge which can (for galaxies with a prominent bulge) dominate the light profile.
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In order to explore local large-scale structures and velocity fields, accurate galaxy distance measures are needed. We now extend the well-tested recipe for calibrating the correlation between galaxy rotation rates and luminosities -- capable of providing such distance measures -- to the all-sky, space-based imaging data from the Wide-field Infrared Survey Explorer (WISE) W1 ($3.4mu$m) and W2 ($4.6mu$m) filters. We find a linewidth to absolute magnitude correlation (known as the Tully-Fisher Relation, TFR) of $mathcal{M}^{b,i,k,a}_{W1} = -20.35 - 9.56 (log W^i_{mx} - 2.5)$ (0.54 magnitudes rms) and $mathcal{M}^{b,i,k,a}_{W2} = -19.76 - 9.74 (log W^i_{mx} - 2.5)$ (0.56 magnitudes rms) from 310 galaxies in 13 clusters. We update the I-band TFR using a sample 9% larger than in Tully & Courtois (2012). We derive $mathcal{M}^{b,i,k}_I = -21.34 - 8.95 (log W^i_{mx} - 2.5)$ (0.46 magnitudes rms). The WISE TFRs show evidence of curvature. Quadratic fits give $mathcal{M}^{b,i,k,a}_{W1} = -20.48 - 8.36 (log W^i_{mx} - 2.5) + 3.60 (log W^i_{mx} - 2.5)^2$ (0.52 magnitudes rms) and $mathcal{M}^{b,i,k,a}_{W2} = -19.91 - 8.40 (log W^i_{mx} - 2.5) + 4.32 (log W^i_{mx} - 2.5)^2$ (0.55 magnitudes rms). We apply an I-band -- WISE color correction to lower the scatter and derive $mathcal{M}_{C_{W1}} = -20.22 - 9.12 (log W^i_{mx} - 2.5)$ and $mathcal{M}_{C_{W2}} = -19.63 - 9.11 (log W^i_{mx} - 2.5)$ (both 0.46 magnitudes rms). Using our three independent TFRs (W1 curved, W2 curved and I-band), we calibrate the UNION2 supernova Type Ia sample distance scale and derive $H_0 = 74.4 pm 1.4$(stat) $pm 2.4$(sys) kms$^{-1}$ Mpc$^{-1}$ with 4% total error.
We explore the use of the baryonic Tully-Fisher relation (bTFR) as a new distance indicator. Advances in near-IR imaging and stellar population models, plus precise rotation curves, have reduced the scatter in the bTFR such that distance is the dominant source of uncertainty. Using 50 galaxies with accurate distances from Cepheids or tip magnitude of the red giant branch, we calibrate the bTFR on a scale independent of $H_o$. We then apply this calibrated bTFR to 95 independent galaxies from the SPARC sample, using CosmicFlows-3 velocities, to deduce the local value of $H_o$. We find $H_o$ = 75.1 +/- 2.3 (stat) +/- 1.5 (sys) km s$^{-1}$ Mpc$^{-1}$.
(Abridged) We aim at measuring the near-infrared photometry, and deriving the mass, age, temperature, and surface gravity of WISE J085510.74-071442.5 (J0855-0714), which is the coolest known object beyond the Solar System as of today. We use publicly available data from the archives of the HST and the VLT to determine the emission of this source at 1.153 micron (F110W) and 1.575 micron (CH_4). J0855-0714 is detected at both wavelengths with signal-to-noise ratio of ~10 (F110W) and ~4 (CH_4-off) at the peak of the corresponding PSFs. This is the first detection of J0855-0714 in the H-band. We measure 26.31 +/- 0.10 and 23.22 +/- 0.35 mag in F110W and CH_4 (Vega system). J0855-0714 remains unresolved in the HST images that have a spatial resolution of 0.22. Companions at separations of 0.5 AU (similar brightness) and at ~1 AU (~1 mag fainter in the F110W filter) are discarded. By combining the new data with published photometry, we build the spectral energy distribution of J0855-0714 from 0.89 to 22.09 micron, and contrast it against state-of-the-art solar-metallicity models of planetary atmospheres. We determine a temperature of 225-250 K, a bolometric luminosity of log L/Lsol = -8.57, and a high surface gravity of log g = 5.0 (cm/s2), which suggests an old age although such a high gravity is not fully compatible with evolutionary models. After comparison with the cooling theory for brown dwarfs and planets, we infer a mass in the interval 2-10 Mjup for ages of 1-12 Gyr and log g > 3.5 (cm/s2). At the age of the Sun, J0855-0714 would be a ~5-Mjup free-floating planetary-mass object. J0855-0714 may represent the old image of the free-floating planetary-mass objects of similar mass discovered in star-forming regions and young stellar clusters. As many J0855-0714-like objects as M5-L2 stars may be expected to populate the solar neighborhood.
We present an all-sky sample of ~ 1.4 million AGNs meeting a two color infrared photometric selection criteria for AGNs as applied to sources from the Wide-Field Infrared Survey Explorer final catalog release (AllWISE). We assess the spatial distribution and optical properties of our sample and find that the results are consistent with expectations for AGNs. These sources have a mean density of ~ 38 AGNs per square degree on the sky, and their apparent magnitude distribution peaks at g ~ 20, extending to objects as faint as g ~ 26. We test the AGN selection criteria against a large sample of optically-identified stars and determine the leakage (that is, the probability that a star detected in an optical survey will be misidentified as a QSO in our sample) rate to be < 4.0 x 10^-5. We conclude that our sample contains almost no optically-identified stars (< 0.041%), making this sample highly promising for future celestial reference frame work by significantly increasing the number of all-sky, compact extragalactic objects. We further compare our sample to catalogs of known AGNs/QSOs and find a completeness value of > 84% (that is, the probability of correctly identifying a known AGN/QSO is at least 84%) for AGNs brighter than a limiting magnitude of R < 19. Our sample includes approximately 1.1 million previously uncatalogued AGNs.
Recent observational results found a bend in the Tully-Fisher Relation in such a way that low mass systems lay below the linear relation described by more massive galaxies. We intend to investigate the origin of the observed features in the stellar and baryonic Tully-Fisher relations and analyse the role played by galactic outflows on their determination. Cosmological hydrodynamical simulations which include Supernova feedback were performed in order to follow the dynamical evolution of galaxies. We found that Supernova feedback is a fundamental process in order to reproduce the observed trends in the stellar Tully-Fisher relation. Simulated slow rotating systems tend to have lower stellar masses than those predicted by the linear fit to the massive end of the relation, consistently with observations. This feature is not present if Supernova feedback is turned off. In the case of the baryonic Tully-Fisher relation, we also detect a weaker tendency for smaller systems to lie below the linear relation described by larger ones. This behaviour arises as a result of the more efficient action of Supernovae in the regulation of the star formation process and in the triggering of powerful galactic outflows in shallower potential wells which may heat up and/or expel part of the gas reservoir.
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