We image the spatial extent of a cool galactic outflow with fine structure Fe II\(^*\) emission and resonant Mg II emission in a gravitationally lensed star-forming galaxy at \(z = 1.70347\). The Fe ...II\(^*\) and Mg II (continuum-subtracted) emissions span out to radial distances of \(\sim\)14.33 kpc and 26.5 kpc, respectively, with maximum spatial extents of \(\sim\)21 kpc for Fe II\(^*\) emission and \(\sim\)30 kpc for Mg II emission. Mg II residual emission is patchy and covers a total area of \(\sim\)184 kpc\(^2\), constraining the minimum area covered by the outflowing gas to be \(\sim\)13% of the total area. Mg II emission is asymmetric and shows \(\sim\)21% more extended emission along the declination direction. We constrain the covering fractions of the Fe II\(^*\) and Mg II emission as a function of radial distance and characterize them with a power law model. The Mg II 2803 emission line shows two kinematically distinct emission components, and may correspond to two distinct shells of outflowing gas with a velocity separation of \(\Delta v \sim\) 400 km/s. By using multiple images with different magnifications of the galaxy in the image plane, we trace the Fe II\(^*\), Mg II emissions around three individual star-forming regions. In all cases, both the Fe II\(^*\) and Mg II emissions are more spatially extended compared to the star forming regions traced by the O II emission. These findings provide robust constraints on the spatial extent of the outflowing gas, and combined with outflow velocity and column density measurements will give stringent constraints on mass outflow rates of the galaxy.
Using the combined resolving power of the Hubble Space Telescope and gravitational lensing, we resolve star-forming structures in a z~2.5 galaxy on scales much smaller than the usual kiloparsec ...diffraction limit of HST. SGAS J111020.0+645950.8 is a clumpy, star forming galaxy lensed by the galaxy cluster SDSS J1110+6459 at z = 0.659, with a total magnification ~30x across the entire arc. We use a hybrid parametric/non-parametric strong lensing mass model to compute the deflection and magnification of this giant arc, reconstruct the light distribution of the lensed galaxy in the source plane, and resolve the star formation into two dozen clumps. We develop a forward-modeling technique to model each clump in the source plane. We ray trace the model to the image plane, convolve with the instrumental point spread function (PSF), and compare with the GALFIT model of the clumps in the image plane, which decomposes clump structure from more extended emission. This technique has the advantage, over ray tracing, by accounting for the asymmetric lensing shear of the galaxy in the image plane and the instrument PSF. At this resolution, we can begin to study star formation on a clump-by-clump basis, toward the goal of understanding feedback mechanisms and the buildup of exponential disks at high redshift.
We probe the spatial distribution of outflowing gas along four lines of sight separated by up to 6 kpc in a gravitationally-lensed star-forming galaxy at z=1.70. Using MgII and FeII emission and ...absorption as tracers, we find that the clumps of star formation are driving galactic outflows with velocities of -170 to -250 km/sec. The velocities of MgII emission are redshifted with respect to the systemic velocities of the galaxy, consistent with being back-scattered. By contrast, the FeII fluorescent emission lines are either slightly blueshifted or at the systemic velocity of the galaxy. Taken together, the velocity structure of the MgII and FeII emission is consistent with arising through scattering in galactic winds. Assuming a thin shell geometry for the out owing gas, the estimated masses carried out by these outfows are large (> 30 - 50 \(\rm{M_{\odot} yr^{-1}}\)), with mass loading factors several times the star-formation rate. Almost 20% to 50% of the blueshifted absorption probably escapes the gravitational potential of the galaxy. In this galaxy, the outflow is "locally sourced", that is, the properties of the outflow in each line of sight are dominated by the properties of the nearest clump of star formation; the wind is not global to the galaxy. The mass outflow rates and the momentum flux carried out by outflows in individual star forming knots of this object are comparable to that of starburst galaxies in the local Universe.
We present the discovery of two new 10 day period giant planets from the Transiting Exoplanet Survey Satellite mission, whose masses were precisely determined using a wide diversity of ground-based ...facilities. TOI-481 b and TOI-892 b have similar radii (0.99 ± 0.01 R(J) and 1.07 ± 0.02 R(J), respectively), and orbital periods (10.3311 days and 10.6266 days, respectively), but significantly different masses (1.53 ± 0.03 M(J) versus 0.95 ± 0.07 M(J), respectively). Both planets orbit metal-rich stars (Fe/HG = +0.26 ± 0.05 dex and Fe/H = +0.24 ± 0.05 for TOI-481 and TOI-892, respectively) but at different evolutionary stages. TOI-481 is a M(*) = 1.14 ± 0.02 Mꙩ, R(*) = 1.66 ± 0.02 Rꙩ G-type star (T(eff) = 5735 ± 72 K), that with an age of 6.7 Gyr, is in the turn-off point of the main sequence. TOI-892 on the other hand, is a F-type dwarf star (T(eff) = 6261 ± 80 K), which has a mass of M(*) = 1.28 ± 0.03 Mꙩ and a radius of R(*) = 1.39 ± 0.02 Rꙩ. TOI-481 b and TOI-892 b join the scarcely populated region of transiting gas giants with orbital periods longer than 10 days, which is important to constrain theories of the formation and structure of hot Jupiters.
We present a Hubble Space Telescope (HST) weak gravitational lensing study of nine distant and massive galaxy clusters with redshifts \(1.0 \lesssim z \lesssim 1.7\) (\(z_\mathrm{median} = 1.4\)) and ...Sunyaev Zel'dovich (SZ) detection significance \(\xi > 6.0\) from the South Pole Telescope Sunyaev Zel'dovich (SPT-SZ) survey. We measured weak lensing galaxy shapes in HST/ACS F606W and F814W images and used additional observations from HST/WFC3 in F110W and VLT/FORS2 in \(U_\mathrm{HIGH}\) to preferentially select background galaxies at \(z\gtrsim 1.8\), achieving a high purity. We combined recent redshift estimates from the CANDELS/3D-HST and HUDF fields to infer an improved estimate of the source redshift distribution. We measured weak lensing masses by fitting the tangential reduced shear profiles with spherical Navarro-Frenk-White (NFW) models. We obtained the largest lensing mass in our sample for the cluster SPT-CLJ2040\(-\)4451, thereby confirming earlier results that suggest a high lensing mass of this cluster compared to X-ray and SZ mass measurements. Combining our weak lensing mass constraints with results obtained by previous studies for lower redshift clusters, we extended the calibration of the scaling relation between the unbiased SZ detection significance \(\zeta\) and the cluster mass for the SPT-SZ survey out to higher redshifts. We found that the mass scale inferred from our highest redshift bin (\(1.2 < z < 1.7\)) is consistent with an extrapolation of constraints derived from lower redshifts, albeit with large statistical uncertainties. Thus, our results show a similar tendency as found in previous studies, where the cluster mass scale derived from the weak lensing data is lower than the mass scale expected in a Planck \(\nu\Lambda\)CDM (i.e. \(\nu\) \(\Lambda\) Cold Dark Matter) cosmology given the SPT-SZ cluster number counts.
We present Atacama Large Millimeter/submillimeter Array observations of CO lines and dust continuum emission of the source RCSGA 032727--132609, a young \(z=1.7\) low-metallicity starburst galaxy. ...The CO(3-2) and CO(6-5) lines, and continuum at rest-frame \(450\,\mu m\) are detected and show a resolved structure in the image plane. We use the corresponding lensing model to obtain a source plane reconstruction of the detected emissions revealing intrinsic flux density of \(S_{450\,\mu m}=23.5_{-8.1}^{+26.8}\) \(\mu\)Jy and intrinsic CO luminosities \(L'_{\rm CO(3-2)}=2.90_{-0.23}^{+0.21}\times10^{8}\) \({\rm K\,km\,s^{-1}\,pc^{2}}\) and \(L'_{\rm CO(6-5)}=8.0_{-1.3}^{+1.4}\times10^{7}\) \({\rm K\,km\,s^{-1}\,pc^{2}}\). We used the resolved properties in the source plane to obtain molecular gas and star-formation rate surface densities of \(\Sigma_{\rm H2}=16.2_{-3.5}^{+5.8}\,{\rm M}_{\odot}\,{\rm pc}^{-2}\) and \(\Sigma_{\rm SFR}=0.54_{-0.27}^{+0.89}\,{\rm M}_{\odot}\,{\rm yr}^{-1}\,{\rm kpc}^{-2}\) respectively. The intrinsic properties of RCSGA 032727--132609 show an enhanced star-formation activity compared to local spiral galaxies with similar molecular gas densities, supporting the ongoing merger-starburst phase scenario. RCSGA 032727--132609 also appears to be a low--density starburst galaxy similar to local blue compact dwarf galaxies, which have been suggested as local analogs to high-redshift low-metallicity starburst systems. Finally, the CO excitation level in the galaxy is consistent with having the peak at \({\rm J}\sim5\), with a higher excitation concentrated in the star-forming clumps.
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