We present our study on the spatially resolved H and M* relation for 536 star-forming and 424 quiescent galaxies taken from the MaNGA survey. We show that the star formation rate surface density ( ), ...derived based on the H emissions, is strongly correlated with the M* surface density ( ) on kiloparsec scales for star-forming galaxies and can be directly connected to the global star-forming sequence. This suggests that the global main sequence may be a consequence of a more fundamental relation on small scales. On the other hand, our result suggests that ∼20% of quiescent galaxies in our sample still have star formation activities in the outer region with lower specific star formation rate (SSFR) than typical star-forming galaxies. Meanwhile, we also find a tight correlation between and for LI(N)ER regions, named the resolved "LI(N)ER" sequence, in quiescent galaxies, which is consistent with the scenario that LI(N)ER emissions are primarily powered by the hot, evolved stars as suggested in the literature.
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 processes that regulate star formation are essential to understand how galaxies evolve. We present the relation between star formation rate density, ΣSFR , and hydrostatic mid-plane ...pressure,Ph, for 4260 star-forming regions of kpc size located in 96 galaxies included in the EDGE-CALIFA survey covering a wide range of stellar masses and morphologies. We find that these two parameters are tightly correlated, showing a smaller scatter in comparison to other star-forming relations. A power law, with a slightly sublinear index, is a good representation of this relation. Its residuals show a significant anticorrelation with both stellar age and metallicity whereas the total stellar mass may also play a secondary role in shaping the ΣSFR–Ph relation. For actively star-forming regions, we find that the effective feedback momentum per unit stellar mass (p*/m*), measured from thePh/ΣSFR ratio increases withPh. The median value of this ratio for all the sampled regions is larger than the expected momentum just from supernovae explosions. Morphology of the galaxies, including bars, does not seem to have a significant impact in the ΣSFR–Ph relation. Our analysis indicates that local ΣSFR self-regulation comes mainly from momentum injection to the interstellar medium from supernovae explosions. However, other mechanisms in disc galaxies may also play a significant role in shaping the ΣSFR at kpc scales. Our results also suggest thatPh is the main parameter that modulates star formation at kpc scales, rather than individual components of the baryonic mass.
We determine the local metallicity of the ionized gas for more than 9.2 × 105 star-forming regions (spaxels) located in 1023 nearby galaxies included in the Sloan Digital Sky Survey-IV MaNGA integral ...field spectroscopy unit survey. We use the dust extinction derived from the Balmer decrement and the stellar template fitting in each spaxel to estimate the local gas and stellar mass densities, respectively. We also use the measured rotation curves to determine the local escape velocity (Vesc). We then analyze the relationships between the local metallicity and both the local gas fraction ( ) and Vesc. We find that metallicity decreases with both increasing and decreasing Vesc. By examining the residuals in these relations we show that the gas fraction plays a more primary role in the local chemical enrichment than does Vesc. We show that the gas-regulator model of chemical evolution provides a reasonable explanation of the metallicity on local scales. The best-fit parameters for this model are consistent with the metal loss caused by momentum-driven galactic outflows. We also argue that both the gas fraction and the local escape velocity are connected to the local stellar surface density, which in turn is a tracer of the epoch at which the dominant local stellar population formed.
We present the integrated stellar mass-metallicity relation (MZR) for more than 1700 galaxies included in the integral field area SDSS-IV MaNGA survey. The spatially resolved data allow us to ...determine the metallicity at the same physical scale (effective radius, Reff) using a heterogeneous set of 10 abundance calibrators. In addition to scale factors, the shape of the MZR is similar for all calibrators, consistent with those reported previously using single-fiber and integral field spectroscopy. We compare the residuals of this relation against the star formation rate (SFR) and specific SFR (sSFR). We do not find a strong secondary relation of the MZR with either SFR or sSFR for any of the calibrators, in contrast with previous single-fiber spectroscopic studies. Our results agree with a scenario in which metal enrichment happens at local scales, with global outflows playing a secondary role in shaping the chemistry of galaxies and cold-gas inflows regulating the stellar formation.
ABSTRACT
We present a detailed exploration of the stellar mass versus gas-phase metallicity relation (MZR) using integral field spectroscopy data obtained from ∼1000 galaxies observed by the SAMI ...galaxy survey. These spatially resolved spectroscopic data allow us to determine the metallicity within the same physical scale (Reff) for different calibrators. The shape of the MZ relations is very similar between the different calibrators, while there are large offsets in the absolute values of the abundances. We confirm our previous results derived using the spatially resolved data provided by the CALIFA and MaNGA surveys: (1) we do not find any significant secondary relation of the MZR with either the star formation rate (SFR) or the specific SFR (SFR/M*) for any of the calibrators used in this study, based on the analysis of the individual residuals; (2) if there is a dependence with the SFR, it is weaker than the reported one (rc ∼ −0.3), it is confined to the low-mass regime (M* < 109 M⊙) or high-SFR regimes, and it does not produce any significant improvement in the description of the average population of galaxies. The aparent disagreement with published results based on single-fibre spectroscopic data could be due to (i) the interpretation of the secondary relation itself; (ii) the lower number of objects sampled at the low-mass regime by the current study; or (iii) the presence of extreme star-forming galaxies that drive the secondary relation in previous results.
We use optical integral-field spectroscopic (IFS) data from 103 nearby galaxies at different stages of the merging event, from close pairs to merger remnants provided by the CALIFA survey, to study ...the impact of the interaction in the specific star formation and oxygen abundance on different galactic scales. To disentangle the effect of the interaction and merger from internal processes, we compared our results with a control sample of 80 non-interacting galaxies. We confirm the moderate enhancement (×2–3 times) of specific star formation for interacting galaxies in central regions as reported by previous studies; however, the specific star formation is comparable when observed in extended regions. We find that control and interacting star-forming galaxies have similar oxygen abundances in their central regions, when normalized to their stellar masses. Oxygen abundances of these interacting galaxies seem to decrease compared to the control objects at the large aperture sizes measured in effective radius. Although the enhancement in central star formation and lower metallicities for interacting galaxies have been attributed to tidally induced inflows, our results suggest that other processes such as stellar feedback can contribute to the metal enrichment in interacting galaxies.
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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.
ABSTRACT
We present a new catalogue of H ii regions based on the integral field spectroscopy (IFS) data of the extended CALIFA and PISCO samples. The selection of H ii regions was based on two ...assumptions: a clumpy structure with high contrast of H α emission and an underlying stellar population comprising young stars. The catalogue provides the spectroscopic information of 26 408 individual regions corresponding to 924 galaxies, including the flux intensities and equivalent widths of 51 emission lines covering the wavelength range between 3745 and 7200 Å. To our knowledge, this is the largest catalogue of spectroscopic properties of H ii regions. We explore a new approach to decontaminate the emission lines from diffuse ionized gas contribution. This diffuse gas correction was estimated to correct every emission line within the considered spectral range. With the catalogue of H ii regions corrected, new demarcation lines are proposed for the classical diagnostic diagrams. Finally, we study the properties of the underlying stellar populations of the H ii regions. It was found that there is a direct relationship between the ionization conditions on the nebulae and the properties of stellar populations besides the physicals condition on the ionized regions.
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