Near-infrared spectroscopy of stellar populations in nearby spiral galaxies

Kotilainen, J. K.; Hyvönen, T.; Reunanen, J.; Ivanov, V. D.

doi:10.1111/j.1365-2966.2012.21425.x

Cited by 17 publications

(24 citation statements)

References 70 publications

(156 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…old stars (Mannucci et al 2005) since, in normal galaxies, most of the mass is in older stars. However, the contribution of red supergiants to the Ksband light, which also exists in normal spiral galaxies (Kotilainen et al 2012), dominates this band in starburst galaxies (Engelbracht et al 1998), which would make Ksband light a useful indicator of recent star formation similar to Hα. In the Ks-band our results are indeed similar to those in Hα: the mean NCR for type Ic is significantly larger than for type II, while types Ib and II are consistent with each other.…”

Section: Differences Between the Sn Typesmentioning

confidence: 99%

Spatial distributions of core-collapse supernovae in infrared-bright galaxies

Kangas

Mattila

Kankare

et al. 2013

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

We have measured the correlation between the locations of core-collapse supernovae (CCSNe) and host galaxy light in the Hα line, near ultraviolet (NUV), R-band and Ks-band to constrain the progenitors of CCSNe using pixel statistics. Our sample consists of 86 CCSNe in 57 infrared (IR) -bright galaxies, of which many are starbursts and ten are luminous infrared galaxies (LIRGs). We also analyse the radial distribution of CCSNe in these galaxies, and determine power-law and exponential fits to CCSN surface density profiles. To probe differences between the SN population of these galaxies and normal spiral galaxies, our results were compared to previous similar studies with samples dominated by normal spiral galaxies where possible. We obtained a normalised scale length of 0.23 +0.03 −0.02 R 25 for the surface density of CCSNe in IR-bright galaxies; less than that derived for CCSNe in a galaxy sample dominated by normal spiral galaxies (0.29 ± 0.01). This reflects a more centrally concentrated population of massive stars in IR-bright galaxies. Furthermore, this centralisation is dominated by a central excess of type Ibc/IIb SNe. This may be due to a top-heavy initial mass function and/or an enhanced close binary fraction in regions of enhanced star formation. Type Ic SNe are most strongly correlated with Hα light and NUV-bright regions, reflecting the shortest lifetime and thus highest mass for type Ic progenitors. Previous studies with samples dominated by normal spiral galaxies have indicated a lower Ibc-Hα correlation than our results do, which may be due to the central excess of type Ibc/IIb SNe in our sample. The difference between types II and Ib is insignificant, suggesting that progenitor mass is not the dominant factor in determining if a SN is of type Ib or II. Similar differences in correlation can be seen in the Ks-band (which in these galaxies is dominated by red supergiants and thus also traces recent star formation), with type Ibc/IIb SNe tracing the Ks-band light better than type II in our sample.

show abstract

Section: Differences Between the Sn Typesmentioning

confidence: 99%

Spatial distributions of core-collapse supernovae in infrared-bright galaxies

Kangas

Mattila

Kankare

et al. 2013

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

show abstract

“…To date, stellar population studies of unresolved galaxies have used mainly the optical absorption line indices, but the NIR spectral features can provide insights into the stellar populations dominated by cool stars (Lançon et al 1999;Riffel et al 2007Riffel et al , 2008Lançon et al 2008;Mármol-Queraltó et al 2009;Kotilainen et al 2012;Lyubenova et al 2012;Riffel et al 2015Riffel et al , 2019. Riffel et al (2019) presented 47 correlations among the different absorption features in the optical and NIR for 16 star-forming galaxies (SFGs henceforth) and for 19 ETGs.…”

Section: Optical/nir Absorption Line Indicesmentioning

confidence: 99%

Modelling simple stellar populations in the near-ultraviolet to near-infrared with the X-shooter Spectral Library (XSL)

Verro,

Trager,

Peletier

et al. 2021

Preprint

View full text Add to dashboard Cite

We present simple stellar population models based on the empirical X-shooter Spectral Library (XSL) from near-ultraviolet (NUV) to near-infrared (NIR) wavelengths. The unmatched characteristics of relatively high resolution and extended wavelength coverage (350-2480 nm, R ∼ 10 000) of the XSL population models bring us closer to bridging optical and NIR studies of intermediate and old stellar populations. It is now common to find good agreement between observed and predicted NUV and optical properties of stellar clusters due to our good understanding of the main-sequence and early giant phases of stars. However, NIR spectra of intermediate-age and old stellar populations are sensitive to cool K and M giants. The asymptotic giant branch, especially the thermally pulsing asymptotic giant branch (TP-AGB), shapes the NIR spectra of 0.5-2 Gyr old stellar populations; the tip of the red giant branch defines the NIR spectra of populations with ages larger than that. We therefore construct sequences of the average spectra of static giants, variable O-rich giants, and C-rich giants to include in the models separately. The models span the metallicity range −2.2 < [Fe/H] < +0.2 and ages above 50 Myr, a broader range in the NIR than in other models based on empirical spectral libraries. We focus on the behaviour of colours and absorption line indices as a function of age and metallicity. Our models reproduce the integrated optical and NIR colours of the Coma cluster galaxies. Furthermore, the XSL models expand the range of predicted values of NIR indices compared to other models based on empirical libraries. Our models make it possible to perform in-depth studies of colours and spectral features consistently throughout the optical and the NIR range to clarify the role of evolved cool stars in stellar populations.

show abstract

“…For example, the luminosity fraction of stars of early spectral types diminishes as the wavelength increases (Bica 1988) and we can actually isolate the asymptotic giant branch (AGB) and red giant branch (RGB) components. Indeed, the contribution of stars outside the AGB-RGB branches is negligible in the K band for all the galaxies independently of their Hubble type (Kotilainen et al 2012). Nevertheless, the AGB and RGB phases are still poorly understood and very difficult to model in the NIR (Röck et al 2017;Riffel et al 2019).…”

Section: Introductionmentioning

confidence: 99%

“…Cesetti et al (2009) performed low-resolution (R = 1000) spectroscopy of 14 early-type galaxies in the wavelength range 1.5-2.4 µm, covering the strong Mg feature at 1.50 µm. Kotilainen et al (2012) focused onto the strongest Mg, Si, and CO features detected in the central regions of a sample of 29 quiescent spiral galaxies, which they measured at a resolution of R ∼ 600 in the H and K bands. Röck (2015) defined and investigated some new line-strength indices in the JHK bands, including those of the aluminium 1.30 µm line and other Mg lines.…”

Section: Introductionmentioning

confidence: 99%

Near-infrared spectroscopic indices for unresolved stellar populations. II. Index measurements

Gasparri,

Morelli,

Ivanov

et al. 2021

Preprint

Self Cite

View full text Add to dashboard Cite

We measured the equivalent width of a large set of near-infrared (NIR, 0.8-2.4 µm) line-strength indices in the XShooter medium-resolution spectra of the central regions of 14 galaxies. We found that two aluminum indices Al at 1.31 µm and Al1 at 1.67 µm and the two CO indices CO1 at 1.56 µm and CO4 at 1.64 µm are tightly correlated with the velocity dispersion. Moreover, the NIR Al and CO1 indices show strong correlations with the optical Mg2 and Mgb indices, which are usually adopted as alpha/Fe-enhancement diagnostics. The molecular FeH1 index at 1.58 µm tightly correlates with the optical Fe and [MgFe]' indices, which are used as total metallicity diagnostics. The NIR Paβ index at 1.28 µm has a behaviour similar to the optical Hβ index, which is a diagnostic of mean age. We defined two new composite indices, Al and [AlFeH], as possible candidates to be used as NIR diagnostics of total metallicity and α/Fe enhancement. The NIR Al index has a strong correlation with the optical Mg2 and Mgb indices, while the [AlFeH] index is tightly correlated with the optical Fe and [MgFe] indices. The distribution of the data points in the NIR Paβ-Al and Paβ-[AlFeH] diagrams mimic that in the optical [MgFe] -Hβ and the Mgb-Fe diagrams, which are widely used to constraint the properties of the unresolved stellar populations. We concluded that some NIR line-strength indices could be useful in studying stellar populations as well as in fine-tuning stellar population models.

show abstract

Near-infrared spectroscopy of stellar populations in nearby spiral galaxies

Cited by 17 publications

References 70 publications

Spatial distributions of core-collapse supernovae in infrared-bright galaxies

Spatial distributions of core-collapse supernovae in infrared-bright galaxies

Modelling simple stellar populations in the near-ultraviolet to near-infrared with the X-shooter Spectral Library (XSL)

Near-infrared spectroscopic indices for unresolved stellar populations. II. Index measurements

Contact Info

Product

Resources

About