Among the hundreds of known hot Jupiters (HJs), only five have been found to have companions on short-period orbits. Within this rare class of multiple planetary systems, the architecture of WASP-47 ...is unique, hosting an HJ (planet-b) with both an inner and an outer sub-Neptunian mass companion (-e and -d, respectively) as well as an additional non-transiting, long-period giant (-c). The small period ratio between planets -b and -d boosts the transit time variation (TTV) signal, making it possible to reliably measure the masses of these planets in synergy with the radial velocity (RV) technique. In this paper, we present new space- and ground-based photometric data of WASP-47b and WASP-47-d, including 11 unpublished light curves from the ESA mission CHaracterising ExOPlanet Satellite (CHEOPS). We analyzed the light curves in a homogeneous way together with all the publicly available data to carry out a global
N
-body dynamical modeling of the TTV and RV signals. We retrieved, among other parameters, a mass and density for planet -d of
M
d
= 15.5 ± 0.8
M
⊕
and
ρ
d
= 1.69 ± 0.22 g cm
−3
, which is in good agreement with the literature and consistent with a Neptune-like composition. For the inner planet (-e), we found a mass and density of
M
e
= 9.0 ± 0.5
M
⊕
and
ρ
e
= 8.1 ± 0.5 g cm
−3
, suggesting an Earth-like composition close to other ultra-hot planets at similar irradiation levels. Though this result is in agreement with previous RV plus TTV studies, it is not in agreement with the most recent RV analysis (at 2.8
σ
), which yielded a lower density compatible with a pure silicate composition. This discrepancy highlights the still unresolved issue of suspected systematic offsets between RV and TTV measurements. In this paper, we also significantly improve the orbital ephemerides of all transiting planets, which will be crucial for any future follow-up.
We present GALEX far-ultraviolet (FUV) and near-ultraviolet (NUV) as well as SDSS g, r, i photometry and structural parameters for the Herschel Reference Survey, a magnitude-, volume-limited sample ...of nearby galaxies in different environments. We use this unique dataset to investigate the ultraviolet (UV) structural scaling relations of nearby galaxies and to determine how the properties of the UV disk vary with atomic hydrogen content and environment. We find a clear change of slope in the stellar mass vs. effective surface brightness relation when moving from the optical to the UV, with more massive galaxies having brighter optical but fainter UV surface brightnesses than smaller systems. A similar change of slope is also seen in the radius vs. surface brightness relation. By comparing our observations with the predictions of a simple multi-zone chemical model of galaxy evolution, we show that these findings are a natural consequence of a much more efficient inside-out growth of the stellar disk in massive galaxies. We confirm that isophotal radii are always a better proxy for the size of the stellar/star-forming disk than effective quantities and we show that the extent of the UV disk (normalized to the optical size) is strongly correlated to the integrated Hi gas fraction. This relation still holds even when cluster spirals are considered, with Hi-deficient systems having less extended star-forming disks than Hi-normal galaxies. Interestingly, the star formation in the inner part of Hi-deficient galaxies is significantly less affected by the removal of the atomic hydrogen, as expected in a simple ram-pressure stripping scenario. These results suggest that it is the amount of Hi that regulates the growth of the star-forming disk in the outskirts of galaxies.
We present the discovery of two small planets transiting HD 93963A (TOI-1797), a GOV star (
M
*
= 1.109 ± 0.043
M
⊙
,
R
*
= 1.043 ± 0.009
R
⊙
) in a visual binary system. We combined TESS and CHEOPS ...space-borne photometry with MuSCAT 2 ground-based photometry, ‘Alopeke and PHARO high-resolution imaging, TRES and FIES reconnaissance spectroscopy, and SOPHIE radial velocity measurements. We validated and spectroscopically confirmed the outer transiting planet HD 93963 A c, a sub-Neptune with an orbital period of
P
c
≈ 3.65 d that was reported to be a TESS object of interest (TOI) shortly after the release of Sector 22 data. HD 93963 A c has amass of
M
c
= 19.2 ± 4.1
M
⊕
and a radius of
R
c
= 3.228 ± 0.059
R
⊕
, implying a mean density of
ρ
c
= 3.1 ± 0.7 g cm
-3
. The inner object, HD 93963 A b, is a validated 1.04 d ultra-short period (USP) transiting super-Earth that we discovered in the TESS light curve and that was not listed as a TOI, owing to the low significance of its signal (TESS signal-to-noise ratio ≈6.7, TESS + CHEOPS combined transit depth
D
b
= 141.5
−8.3
+8.5
ppm). We intensively monitored the star with CHEOPS by performing nine transit observations to confirm the presence of the inner planet and validate the system. HD 93963 A b is the first small (
R
b
= 1.35 ± 0.042
R
⊕
) USP planet discovered and validated by TESS and CHEOPS. Unlike planet c, HD 93963 Ab is not significantly detected in our radial velocities (
M
b
= 7.8 ± 3.2
M
⊕
). The two planets are on either side of the radius valley, implying that they could have undergone completely different evolution processes. We also discovered a linear trend in our Doppler measurements, suggesting the possible presence of a long-period outer planet. With a
V
-band magnitude of 9.2, HD 93963 A is among the brightest stars known to host a USP planet, making it one of the most favourable targets for precise mass measurement via Doppler spectroscopy and an important laboratory to test formation, evolution, and migration models of planetary systems hosting ultra-short period planets.
We report the discovery of diffuse far-infrared and far-ultraviolet emission projected near the interacting pair NGC 4435/4438, in the Virgo cluster. This feature spatially coincides with a ...well-known low surface-brightness optical plume, usually interpreted as tidal debris. If extragalactic, this stream would represent not only one of the clearest examples of intracluster dust, but also a rare case of intracluster molecular hydrogen and large-scale intracluster star formation. However, the ultraviolet, far-infrared, Hi and CO emission as well as the dynamics of this feature are extremely unusual for tidal streams but are typical of Galactic cirrus clouds. In support to the cirrus scenario, we show that a strong spatial correlation between far-infrared and far-ultraviolet cirrus emission is observed across the centre of the Virgo cluster, over a scale of several degrees. This study demonstrates how dramatic Galactic cirrus contamination can be, even at optical and ultraviolet wavelengths and at high galactic latitudes. If ignored, the presence of diffuse light scattered by Galactic dust clouds could significantly bias our interpretation of low surface-brightness features and diffuse light observed around galaxies and in clusters of galaxies.
We report the first systematic study of the submillimeter water vapor rotational emission lines in infrared (IR) galaxies based on the Fourier Transform Spectrometer (FTS) data of Herschel SPIRE. ...Among the 176 galaxies with publicly available FTS data, 45 have at least one H sub(2)O emission line detected. The H sub(2)O line luminosities range from ~1 x 10 super(5) L sub(midot in circle) to ~5 x 10 super(7) L sub(middot in circle) while the total IR luminosities (L sub(IR)) have a similar spread (~1-300 x 10 super(10) L sub(middot in circle)). In addition, emission lines of H sub(2)O+ and (ProQuest: Formulae and/or non-USASCII text omitted) are also detected. H sub(2)O is found, for most galaxies, to be the strongest molecular emitter after CO in FTS spectra. The luminosity of the five most important H sub(2)O lines is near-linearly correlated with L sub(IR), regardless of whether or not strong active galactic nucleus signature is present. However, the luminosity of H sub(2)O(2 sub(11)-2 sub(0 2)) and H sub(2)O(2 sub(20)-2 sub(1 1)) appears to increase slightly faster than linear with L sub(IR). Although the slope turns out to be slightly steeper when z ~ 2-A ULIRGs are included, the correlation is still closely linear. We find that L sub(H2O)/L sub(IR) decreases with increasing functionof sub(25)/functionof sub(60), but see no dependence on functionof sub(60)/functionof sub(100), possibly indicating that very warm dust contributes little to the excitation of the submillimeter H sub(2)O lines. The average spectral line energy distribution (SLED) of the entire sample is consistent with individual SLEDs and the IR pumping plus collisional excitation model, showing that the strongest lines are H sub(2)O(2 sub(02)-1 sub(1 1)) and H sub(2)O(3 sub(21)-3 sub(1 2)).
We present submillimetre (submm) continuum images of the fields of three luminous quasars at z > 5, obtained at 850 and 450 μm using the Submillimetre Common-User Bolometer Array on the James Clerk ...Maxwell Telescope (JCMT). N-body simulations predict that such quasars evolve to become the central dominant galaxies of massive clusters at z= 0, but at z= 5–6 they are actively forming stars and surrounded by a rich protofilamentary structure of young galaxies. Our purpose in taking these images was to search for other luminous, star-forming galaxies in the vicinity of the signpost active galactic nuclei and thus associated with such a protocluster. Two of the quasar host galaxies are luminous submm galaxies (SMGs) in their own right, implying star formation rates ∼103M⊙ yr−1. Despite the coarse 850-μm beam of the JCMT, our images show evidence of extended emission on a scale of ∼100 kpc from at least one quasar – indicative of a partially resolved merger or a colossal host galaxy. In addition, at >3σ significance we detect 12 (5) SMGs at 850 μm (450 μm) in the surrounding fields. Number counts of these SMGs are comparable with those detected in the fields of z∼ 4 radio galaxies, and both samples are, at the bright end, overabundant by a factor of ≈4 relative to blank-field submm surveys. Whilst the redshift-sensitive 850 μm/450 μm and 850 μm/1.4 GHz flux density ratios indicate that some of these SMGs are likely foreground objects, the counts suggest that ∼60 per cent lie in the same large-scale structures as the quasars.
We use Herschel Space Observatory data to place observational constraints on the peak and Rayleigh-Jeans slope of dust emission observed at 70–500 μm in the nearby spiral galaxy M81. We find that the ...ratios of wave bands between 160 and 500 μm are primarily dependent on radius but that the ratio of 70 to 160 μm emission shows no clear dependence on surface brightness or radius. These results along with analyses of the spectral energy distributions imply that the 160–500 μm emission traces 15–30 K dust heated by evolved stars in the bulge and disc whereas the 70 μm emission includes dust heated by the active galactic nucleus and young stars in star forming regions.
Luminous infrared galaxies (LIR > 1011 L⊙) are often associated with interacting galactic systems and are thought to be powered by merger-induced starbursts and/or dust-enshrouded active galactic ...nucleus. In such systems, the evolution of the dense, star-forming molecular gas as a function of merger separation is of particular interest. Here, we present observations of the CO(3–2) emission from a sample of luminous infrared galaxy mergers that span a range of galaxy–galaxy separations. The excitation of the molecular gas is studied by examining the CO(3–2)/CO(1–0) line ratio, r31, as a function of merger extent. We find these line ratios, r31, to be consistent with kinetic temperatures of Tk= (30–50) K and gas densities of . We also find weak correlations between r31 and both merger progression and star formation efficiency LFIR/LCO(1-0). These correlations show a tendency for gas excitation to increase as the merger progresses and the star formation efficiency rises. To conclude, we calculate the contributions of the CO(3–2) line to the 850-μm fluxes measured with SCUBA (Submillimetre Common-User Bolometer Array), which are seen to be significant (∼22 per cent).
We present, for the first time, a statistical study of NII 205 mu m line emission for a large sample of local luminous infrared galaxies using Herschel Spectral and Photometric Imaging Receiver ...Fourier Transform Spectrometer (SPIRE FTS) data. For our sample of galaxies, we investigate the correlation between the NII luminosity (L(N II) and the total infrared luminosity (L sub(IR)), as well as the dependence of L sub(NII)/L sub(IR) ratio on L sub(IR), far-infrared colors (IRAS functionof sub(60)/functionof sub(100)), and the OIII 88 mu m to NII luminosity ratio. We find that LNII correlates almost linearly with L sub(IR) for non-active galactic nucleus galaxies (all having L sub(IR) < 10 super(12) L sub(middot in center)) in our sample, which implies that L sub(N II) can serve as a star formation rate tracer which is particularly useful for high-redshift galaxies that will be observed with forthcoming submillimeter spectroscopic facilities such as the Atacama Large Millimeter/submillimeter Array. Our analysis shows that the deviation from the mean L sub(N II)-L sub(IR) relation correlates with tracers of the ionization parameter, which suggests that the scatter in this relation is mainly due to the variations in the hardness, and/or ionization parameter, of the ambient galactic UV field among the sources in our sample.
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