A full appreciation of the role played by gas metallicity (Z), star formation rate (SFR) and stellar mass (M
*) is fundamental to understanding how galaxies form and evolve. The connections between ...these three parameters at different redshifts significantly affect galaxy evolution, and thus provide important constraints for galaxy evolution models. Using data from the Sloan Digital Sky Survey-Data Release 7 (SDSS-DR7) and the Galaxy and Mass Assembly (GAMA) surveys, we study the relationships and dependences between SFR, Z and M
*, as well as the Fundamental Plane for star-forming galaxies. We combine both surveys using volume-limited samples up to a redshift of z 0.36. The GAMA and SDSS surveys complement each other when analysing the relationships between SFR, M
* and Z. We present evidence for SFR and metallicity evolution to z ∼ 0.2. We study the dependences between SFR, M
*, Z and specific SFR (SSFR) on the M
*-Z, M
*-SFR, M
*-SSFR, Z-SFR and Z-SSFR relations, finding strong correlations between all. Based on those dependences, we propose a simple model that allows us to explain the different behaviour observed between low- and high-mass galaxies. Finally, our analysis allows us to confirm the existence of a Fundamental Plane, for which M
* = f(Z, SFR) in star-forming galaxies.
Ultra-hot Jupiters are gas giants planets whose dayside temperature is greater than 2200 K as a consequence of the strong irradiation received from the host star. These kinds of objects are perfect ...laboratories to study the chemistry of exoplanetary upper atmospheres via transmission spectroscopy. Exo-atmospheric absorption features are buried in the noise of the in-transit residual spectra. However we can retrieve information of hundreds of atmospheric absorption lines by performing a cross-correlation with an atmospheric transmission model, which allows us to greatly increase the exo-atmospheric signal. The Rossiter–McLaughlin effect and centre-to-limb variation contribute strongly at the high spectral resolution of our data. We present the first detection of Fe
I
and confirmation of absorption features of Fe
II
in the atmosphere of the ultra-hot Jupiter MASCARA-2b/KELT-20b, by using three transit observations with HARPS-N. After combining all transit observations we find a high cross-correlation signal of Fe
I
and Fe
II
with signal-to-noise ratios of 10.5 ± 0.4 and 8.6 ± 0.5, respectively. The peak absorption for both species appear to be blue-shifted with velocities of − 6.3 ± 0.8 km s
−1
for Fe
I
and − 2.8 ± 0.8 km s
−1
for Fe
II
, suggesting the presence of winds from the day- to night-side of the atmosphere of the planet. These results confirm previous studies of this planet and add a new atomic species (Fe
I
) to the long list of detected species in the atmosphere of MASCARA-2b, making it, together with KELT-9b, the most feature-rich ultra-hot Jupiter to date.
Ultra-hot Jupiters are emerging as a new class of exoplanets. Studying their chemical compositions and temperature structures will improve our understanding of their mass loss rate as well as their ...formation and evolution. We present the detection of ionized calcium in the two hottest giant exoplanets – KELT-9b and WASP-33b. By using transit datasets from CARMENES and HARPS-N observations, we achieved high-confidence-level detections of Ca II using the cross-correlation method. We further obtain the transmission spectra around the individual lines of the Ca II H&K doublet and the near-infrared triplet, and measure their line profiles. The Ca II H&K lines have an average line depth of 2.02 ± 0.17% (effective radius of 1.56 Rp) for WASP-33b and an average line depth of 0.78 ± 0.04% (effective radius of 1.47 Rp) for KELT-9b, which indicates that the absorptions are from very high upper-atmosphere layers close to the planetary Roche lobes. The observed Ca II lines are significantly deeper than the predicted values from the hydrostatic models. Such a discrepancy is probably a result of hydrodynamic outflow that transports a significant amount of Ca II into the upper atmosphere. The prominent Ca II detection with the lack of significant Ca I detection implies that calcium is mostly ionized in the upper atmospheres of the two planets.
Abstract
Ultrahot Jupiters are gas giants that orbit so close to their host star that they are tidally locked, causing a permanent hot dayside and a cooler nightside. Signatures of their nonuniform ...atmospheres can be observed with high-resolution transit transmission spectroscopy by resolving time-dependent velocity shifts as the planet rotates and varying areas of the evening and morning terminator are probed. These asymmetric shifts were seen for the first time in iron absorption in WASP-76b. Here, we search for other atoms/ions in the planets transmission spectrum and study the asymmetries in their signals. We detect Li
i
, Na
i
, Mg
i
, Ca
ii
, V
i
, Cr
i
, Mn
i
, Fe
i
, Ni
i
, and Sr
ii
, and tentatively detect H
i
, K
i
, and Co
i
, of which V, Cr, Ni, Sr
ii
, and Co have not been reported before. We notably do not detect Ti or Al, even though these species should be readily observable, and hypothesize this could be due to condensation or cold trapping. We find that the observed signal asymmetries in the detected species can be explained in different ways. We find a relation between the expected condensation or ionization temperatures and the strength of the observed asymmetry, which could indicate rain-out or recombination on the nightside. However, we also find a dependence on the signal broadening, which could imply a two-zoned atmospheric model, in which the lower atmosphere is dominated by a day-to-night wind, while the upper atmosphere is dominated by a vertical wind or outflow. These observations provide a new level of modeling constraint and will aid our understanding of atmospheric dynamics in highly irradiated planets.
High resolution transit spectroscopy has proven to be a reliable technique for the characterization of the chemical composition of exoplanet atmospheres. Taking advantage of the broad spectral ...coverage of the CARMENES spectrograph, we initiated a survey aimed at characterizing a broad range of planetary systems. Here, we report our observations of three transits of GJ 3470 b with CARMENES in search of He (2
3
S) absorption. On one of the nights, the He
I
region was heavily contaminated by OH
−
telluric emission and, thus, it was not useful for our purposes. The remaining two nights had a very different signal-to-noise ratio (S/N) due to weather. They both indicate the presence of He (2
3
S) absorption in the transmission spectrum of GJ 3470 b, although a statistically valid detection can only be claimed for the night with higher S/N. For that night, we retrieved a 1.5 ± 0.3% absorption depth, translating into a
R
p
(
λ
)∕
R
p
= 1.15 ± 0.14 at this wavelength. Spectro-photometric light curves for this same night also indicate the presence of extra absorption during the planetary transit with a consistent absorption depth. The He (2
3
S) absorption is modeled in detail using a radiative transfer code, and the results of our modeling efforts are compared to the observations. We find that the mass-loss rate,
Ṁ
, is confined to a range of 3 × 10
10
g s
−1
for
T
= 6000 K to 10 × 10
10
g s
−1
for
T
= 9000 K. We discuss the physical mechanisms and implications of the He
I
detection in GJ 3470 b and put it in context as compared to similar detections and non-detections in other Neptune-size planets. We also present improved stellar and planetary parameter determinations based on our visible and near-infrared observations.
The He
I
λ
10833 Å triplet is a powerful tool for characterising the upper atmosphere of exoplanets and tracing possible mass loss. Here, we analysed one transit of GJ 1214 b observed with the ...CARMENES high-resolution spectrograph to study its atmosphere via transmission spectroscopy around the He
I
triplet. Although previous studies using lower resolution instruments have reported non-detections of He
I
in the atmosphere of GJ 1214 b, we report here the first potential detection. We reconcile the conflicting results arguing that previous transit observations did not present good opportunities for the detection of He
I
, due to telluric H
2
O absorption and OH emission contamination. We simulated those earlier observations, and show evidence that the planetary signal was contaminated. From our single non-telluric-contaminated transit, we determined an excess absorption of 2.10
−0.50
+0.45
% (4.6
σ
) with a full width at half maximum (FWHM) of 1.30
−0.25
+0.30
Å. The detection of He
I
is statistically significant at the 4.6
σ
level, but repeatability of the detection could not be confirmed due to the availability of only one transit. By applying a hydrodynamical model and assuming an H/He composition of 98/2, we found that GJ 1214 b would undergo hydrodynamic escape in the photon-limited regime, losing its primary atmosphere with a mass-loss rate of (1.5–18) × 10
10
g s
−1
and an outflow temperature in the range of 2900–4400 K. Further high-resolution follow-up observations of GJ 1214 b are needed to confirm and fully characterise the detection of an extended atmosphere surrounding GJ 1214 b. If confirmed, this would be strong evidence that this planet has a primordial atmosphere accreted from the original planetary nebula. Despite previous intensive observations from space- and ground-based observatories, our He
I
excess absorption is the first tentative detection of a chemical species in the atmosphere of this benchmark sub-Neptune planet.
The mass–metallicity relation revisited with CALIFA Sánchez, S. F; Barrera-Ballesteros, J. K; Sánchez-Menguiano, L ...
Monthly notices of the Royal Astronomical Society,
08/2017, Volume:
469, Issue:
2
Journal Article
Peer reviewed
Open access
Abstract
We present an updated version of the mass–metallicity (MZ) relation using integral field spectroscopy data obtained from 734 galaxies observed by the CALIFA survey. These unparalleled ...spatially resolved spectroscopic data allow us to determine the metallicity at the same physical scale (Re) for different calibrators. We obtain MZ relations with similar shapes for all calibrators, once the scalefactors among them are taken into account. We do not find any significant secondary relation of the MZ relation with either the star formation rate (SFR) or the specific SFR for any of the calibrators used in this study, based on the analysis of the residuals of the best-fitted relation. However, we do see a hint for an (s)SFR-dependent deviation of the MZ relation at low masses (M < 109.5 M⊙), where our sample is not complete. We are thus unable to confirm the results by Mannucci et al. (2010), although we cannot exclude that this result is due to the differences in the analysed data sets. In contrast, our results are inconsistent with the results by Lara-López et al. (2010), and we can exclude the presence of an SFR–mass–oxygen abundance fundamental plane. These results agree with previous findings suggesting that either (1) the secondary relation with the SFR could be induced by an aperture effect in single fibre/aperture spectroscopic surveys, (2) it could be related to a local effect confined to the central regions of galaxies or (3) it is just restricted to the low-mass regime, or a combination of the three effects.
We examine the properties of galaxies in the Galaxies and Mass Assembly (GAMA) survey located in voids with radii >10 h
−1 Mpc. Utilizing the GAMA equatorial survey, 592 void galaxies are identified ...out to z ≈ 0.1 brighter than M
r
= −18.4, our magnitude completeness limit. Using the W
Hα versus N ii/Hα (WHAN) line strength diagnostic diagram, we classify their spectra as star forming, AGN, or dominated by old stellar populations. For objects more massive than 5 × 109 M⊙, we identify a sample of 26 void galaxies with old stellar populations classed as passive and retired galaxies in the WHAN diagnostic diagram, else they lack any emission lines in their spectra. When matched to Wide-field Infrared Survey Explorer mid-IR photometry, these passive and retired galaxies exhibit a range of mid-IR colour, with a number of void galaxies exhibiting 4.6 − 12 colours inconsistent with completely quenched stellar populations, with a similar spread in colour seen for a randomly drawn non-void comparison sample. We hypothesize that a number of these galaxies host obscured star formation, else they are star forming outside of their central regions targeted for single-fibre spectroscopy. When matched to a randomly drawn sample of non-void galaxies, the void and non-void galaxies exhibit similar properties in terms of optical and mid-IR colour, morphology, and star formation activity, suggesting comparable mass assembly and quenching histories. A trend in mid-IR 4.6 − 12 colour is seen, such that both void and non-void galaxies with quenched/passive colours <1.5 typically have masses higher than 1010 M⊙, where internally driven processes play an increasingly important role in galaxy evolution.
Caffeine supplementation (CAFF) has an established ergogenic effect on physical performance and the psychological response to exercise. However, few studies have compared the response to CAFF intake ...among athletes of different competition level. This study compares the acute effects of CAFF on anaerobic performance, mood and perceived effort in elite and moderately-trained recreational athletes.
Participants for this randomized, controlled, crossover study were 8 elite athletes (in the senior boxing national team) and 10 trained-recreational athletes. Under two experimental conditions, CAFF supplementation (6 mg/kg) or placebo (PLAC), the athletes completed a Wingate test. Subjective exertion during the test was recorded as the rating of perceived exertion (RPE) both at the general level (RPE
) and at the levels muscular (RPE
) and cardiorespiratory (RPE
). Before the Wingate test, participants completed the questionnaires Profiles of Moods States (POMS) and Subjective Vitality Scale (SVS).
In response to CAFF intake, improvements were noted in W
(11.22 ± 0.65 vs 10.70 ± 0.84; p = 0.003; Formula: see text =0.44), W
(8.75 ± 0.55 vs 8.41 0.46; p = 0.001; Formula: see text =0.53) and time taken to reach W
(7.56 ± 1.58 vs 9.11 ± 1.53; p < 0.001; Formula: see text =0.57) both in the elite and trained-recreational athletes. However, only the elite athletes showed significant increases in tension (+ 325%), vigor (+ 31%) and SVS (+ 28%) scores after the intake of CAFF compared to levels recorded under the condition PLAC (p < 0.05). Similarly, levels of vigor after consuming CAFF were significantly higher in the elite than the trained-recreational athletes (+ 5.8%).
CAFF supplementation improved anaerobic performance in both the elite and recreational athletes. However, the ergogenic effect of CAFF on several mood dimensions and subjective vitality was greater in the elite athletes.
We present the PMAS/PPak Integral-field Supernova hosts COmpilation (PISCO), which comprises integral field spectroscopy (IFS) of 232 supernova (SN) host galaxies that hosted 272 SNe, observed over ...several semesters with the 3.5 m telescope at the Calar Alto Observatory (CAHA). PISCO is the largest collection of SN host galaxies observed with wide-field IFS, totaling 466,347 individual spectra covering a typical spatial resolution of ∼380 pc. Focused studies regarding specific SN Ia-related topics will be published elsewhere; this paper aims to present the properties of the SN environments, using stellar population (SP) synthesis, and the gas-phase interstellar medium, providing additional results separating stripped-envelope SNe into their subtypes. With 11,270 H ii regions detected in all galaxies, we present for the first time a statistical analysis of H ii regions, which puts H ii regions that have hosted SNe in context with all other star-forming clumps within their galaxies. SNe Ic are associated with environments that are more metal-rich and have higher EW(H ) and higher star formation rate within their host galaxies than the mean of all H ii regions detected within each host. This in contrast to SNe IIb, which occur in environments that are very different compared to other core-collapse SNe types. We find two clear components of young and old SPs at SNe IIn locations. We find that SNe II fast decliners tend to explode at locations where the SFR is more intense. Finally, we outline how a future dedicated IFS survey of galaxies in parallel to an untargeted SN search would overcome the biases in current environmental studies.
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