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.
Abstract
We study a sample of 28 S0 galaxies extracted from the integral field spectroscopic (IFS) survey Calar Alto Legacy Integral Field Area. We combine an accurate two-dimensional (2D) ...multicomponent photometric decomposition with the IFS kinematic properties of their bulges to understand their formation scenario. Our final sample is representative of S0s with high stellar masses (M⋆/M⊙ > 1010). They lay mainly on the red sequence and live in relatively isolated environments similar to that of the field and loose groups. We use our 2D photometric decomposition to define the size and photometric properties of the bulges, as well as their location within the galaxies. We perform mock spectroscopic simulations mimicking our observed galaxies to quantify the impact of the underlying disc on our bulge kinematic measurements (λ and v/σ). We compare our bulge corrected kinematic measurements with the results from Schwarzschild dynamical modelling. The good agreement confirms the robustness of our results and allows us to use bulge deprojected values of λ and v/σ. We find that the photometric (n and B/T) and kinematic (v/σ and λ) properties of our field S0 bulges are not correlated. We demonstrate that this morpho-kinematic decoupling is intrinsic to the bulges and it is not due to projection effects. We conclude that photometric diagnostics to separate different types of bulges (disc-like versus classical) might not be useful for S0 galaxies. The morpho-kinematics properties of S0 bulges derived in this paper suggest that they are mainly formed by dissipational processes happening at high redshift, but dedicated high-resolution simulations are necessary to better identify their origin.
ABSTRACT
The physical properties of galactic winds are one of the keys to understand galaxy formation and evolution. These properties can be constrained thanks to background quasar lines of sight ...(LOS) passing near star-forming galaxies (SFGs). We present the first results of the MusE GAs FLOw and Wind survey obtained from two quasar fields, which have eight Mg
ii
absorbers of which three have rest equivalent width greater than 0.8 Å. With the new Multi Unit Spectroscopic Explorer (MUSE) spectrograph on the Very Large Telescope (VLT), we detect six (75%) Mg
ii
host galaxy candidates within a radius of 30″ from the quasar LOS. Out of these six galaxy–quasar pairs, from geometrical argument, one is likely probing galactic outflows, where two are classified as “ambiguous,” two are likely probing extended gaseous disks and one pair seems to be a merger. We focus on the wind-pair and constrain the outflow using a high-resolution quasar spectra from the Ultraviolet and Visual Echelle Spectrograph. Assuming the metal absorption to be due to ga;s flowing out of the detected galaxy through a cone along the minor axis, we find outflow velocities in the order of ≈150
(i.e., smaller than the escape velocity) with a loading factor,
, of ≈0.7. We see evidence for an open conical flow, with a low-density inner core. In the future, MUSE will provide us with about 80 multiple galaxy−quasar pairs in two dozen fields.
ABSTRACT We report the discovery of SMSS J160540.18−144323.1, a new ultra metal-poor halo star discovered with the SkyMapper telescope. We measure $\left\rm {Fe}/\rm {H}\right= -6.2 \pm 0.2$ (1D ...LTE), the lowest ever detected abundance of iron in a star. The star is strongly carbon-enhanced, $\left\rm {C}/\rm {Fe}\right = 3.9 \pm 0.2$, while other abundances are compatible with an α-enhanced solar-like pattern with $\left\rm {Ca}/\rm {Fe}\right = 0.4 \pm 0.2$, $\left\rm {Mg}/\rm {Fe}\right = 0.6 \pm 0.2$, $\left\rm {Ti}/\rm {Fe}\right = 0.8 \pm 0.2$, and no significant s- or r-process enrichment, $\left\rm {Sr}/\rm {Fe}\right \lt 0.2$ and $\left\rm {Ba}/\rm {Fe}\right \lt 1.0$ (3σ limits). Population III stars exploding as fallback supernovae may explain both the strong carbon enhancement and the apparent lack of enhancement of odd-Z and neutron-capture element abundances. Grids of supernova models computed for metal-free progenitor stars yield good matches for stars of about $10\, \rm M_\odot$ imparting a low kinetic energy on the supernova ejecta, while models for stars more massive than roughly $20\, \rm M_\odot$ are incompatible with the observed abundance pattern.
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, Letnik:
469, Številka:
2
Journal Article
ABSTRACT
We present and discuss the results of a search for extremely metal-poor stars based on photometry from data release DR1.1 of the SkyMapper imaging survey of the southern sky. In particular, ...we outline our photometric selection procedures and describe the low-resolution (R ≈ 3000) spectroscopic follow-up observations that are used to provide estimates of effective temperature, surface gravity, and metallicity (Fe/H) for the candidates. The selection process is very efficient: of the 2618 candidates with low-resolution spectra that have photometric metallicity estimates less than or equal to −2.0, 41 per cent have Fe/H ≤ −2.75 and only approximately seven per cent have Fe/H > −2.0 dex. The most metal-poor candidate in the sample has Fe/H < −4.75 and is notably carbon rich. Except at the lowest metallicities (Fe/H < −4), the stars observed spectroscopically are dominated by a ‘carbon-normal’ population with C/Fe1D, LTE ≤ +1 dex. Consideration of the A(C)1D, LTE versus Fe/H1D, LTE diagram suggests that the current selection process is strongly biased against stars with A(C)1D, LTE > 7.3 (predominantly CEMP-s) while any bias against stars with A(C)1D, LTE < 7.3 and C/Fe1D,LTE > +1 (predominantly CEMP-no) is not readily quantifiable given the uncertainty in the SkyMapper v-band DR1.1 photometry. We find that the metallicity distribution function of the observed sample has a power-law slope of Δ(Log N)/ΔFe/H = 1.5 ± 0.1 dex per dex for −4.0 ≤ Fe/H ≤ −2.75, but appears to drop abruptly at Fe/H ≈ −4.2, in line with previous studies.
We carry out a direct search for bar-like non-circular flows in intermediate-inclination, gas-rich disc galaxies with a range of morphological types and photometric bar classifications from the first ...data release (DR1) of the Calar Alto Legacy Integral Field Spectroscopy Area (CALIFA) survey. We use the diskfit algorithm to apply rotation only and bisymmetric flow models to H α velocity fields for 49/100 CALIFA DR1 systems that meet our selection criteria. We find satisfactory fits for a final sample of 37 systems. diskfit is sensitive to the radial or tangential components of a bar-like flow with amplitudes greater than 15 km s−1 across at least two independent radial bins in the fit, or ∼2.25 kpc at the characteristic final sample distance of ∼75 Mpc. The velocity fields of 25/37
${(67.6^{+6.6}_{-8.5}\,\mathrm{per\ cent})}$
galaxies are best characterized by pure rotation, although only 17/25
${(68.0^{+7.7}_{-10.4}\,\mathrm{per\ cent})}$
of them have sufficient H α emission near the galaxy centre to afford a search for non-circular flows. We detect non-circular flows in the remaining 12/37
${(32.4^{+8.5}_{-6.6}\,\mathrm{per\ cent})}$
galaxies. We conclude that the non-circular flows detected in 11/12
${(91.7^{+2.8}_{-14.9}\,\mathrm{per\ cent})}$
systems stem from bars. Galaxies with intermediate (AB) bars are largely undetected, and our detection thresholds therefore represent upper limits to the amplitude of the non-circular flows therein. We find 2/23
${(8.7^{+9.6}_{-2.9}\,\mathrm{per\ cent})}$
galaxies that show non-circular motions consistent with a bar-like flow, yet no photometric bar is evident. This suggests that in ∼10 per cent of galaxies either the existence of a bar may be missed completely in photometry or other processes may drive bar-like flows and thus secular galaxy evolution.
Abstract The Lyman alpha (Ly α) line of Hydrogen is a prominent feature in the spectra of star-forming galaxies, usually redshifted by a few hundreds of km s−1 compared to the systemic redshift. This ...large offset hampers follow-up surveys, galaxy pair statistics, and correlations with quasar absorption lines when only Ly α is available. We propose diagnostics that can be used to recover the systemic redshift directly from the properties of the Ly α line profile. We use spectroscopic observations of Ly α emitters for which a precise measurement of the systemic redshift is available. Our sample contains 13 sources detected between z ≈ 3 and z ≈ 6 as part of various multi-unit spectroscopic explorer guaranteed time observations. We also include a compilation of spectroscopic Ly α data from the literature spanning a wide redshift range (z ≈ 0–8). First, restricting our analysis to double-peaked Ly α spectra, we find a tight correlation between the velocity offset of the red peak with respect to the systemic redshift, $V_{\rm peak}^{\rm red}$, and the separation of the peaks. Secondly, we find a correlation between $V_{\rm peak}^{\rm red}$ and the full width at half-maximum of the Ly α line. Fitting formulas to estimate systemic redshifts of galaxies with an accuracy of ≤100 km s−1, when only the Ly α emission line is available, are given for the two methods.
Galaxies are surrounded by large reservoirs of gas, mostly hydrogen, that are fed by inflows from the intergalactic medium and by outflows from galactic winds. Absorption-line measurements along the ...lines of sight to bright and rare background quasars indicate that this circumgalactic medium extends far beyond the starlight seen in galaxies, but very little is known about its spatial distribution. The Lyman-α transition of atomic hydrogen at a wavelength of 121.6 nanometres is an important tracer of warm (about 10
kelvin) gas in and around galaxies, especially at cosmological redshifts greater than about 1.6 at which the spectral line becomes observable from the ground. Tracing cosmic hydrogen through its Lyman-α emission has been a long-standing goal of observational astrophysics
, but the extremely low surface brightness of the spatially extended emission is a formidable obstacle. A new window into circumgalactic environments was recently opened by the discovery of ubiquitous extended Lyman-α emission from hydrogen around high-redshift galaxies
. Such measurements were previously limited to especially favourable systems
or to the use of massive statistical averaging
because of the faintness of this emission. Here we report observations of low-surface-brightness Lyman-α emission surrounding faint galaxies at redshifts between 3 and 6. We find that the projected sky coverage approaches 100 per cent. The corresponding rate of incidence (the mean number of Lyman-α emitters penetrated by any arbitrary line of sight) is well above unity and similar to the incidence rate of high-column-density absorbers frequently detected in the spectra of distant quasars
. This similarity suggests that most circumgalactic atomic hydrogen at these redshifts has now been detected in emission.
H II regions in galaxies are the sites of star formation, so they are special places for understanding the build-up of stellar mass in the universe. The line ratios of this ionized gas are frequently ...used to characterize the ionization conditions. We explore the connections between the ionization conditions and the properties of the overall underlying stellar population in H II regions, in order to uncover the actual physical connection between them. We use the H II regions catalog from the CALIFA survey, which is the largest in existence with more than 5000 H II regions, to explore their distribution across the classical OIII lambda5007/Hbeta vs. NII lambda6583/Halpha diagnostic diagram, and the way it depends on the oxygen abundance, ionization parameter, electron density, and dust attenuation. The results indicate that although H II regions are short-lived events, they are affected by the total underlying stellar population.
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