M101: Spectral Observations of H ii Regions and Their Physical Properties

Hu, Ning; Wang, Enci; Lin, Zhoubin; Kong, Xu; Cheng, F. Z.; Zou, Fan; Fang, Guanwen; Lin, Lin; Mao, Yudong; Wang, Jing; Zhou, Xu; Zhou, Zhiming; Zhu, Yongchun; Zou, Hu

doi:10.3847/1538-4357/aaa6ca

Cited by 19 publications

(22 citation statements)

References 101 publications

(142 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For presentation purposes, the slit length is set to 7 arcsec; however, a 0.7 arcsec × 110.7 arcsec slit was used for (a) and a 0.7 arcsec × 118.7 arcsec slit was used for (b). Hu et al 2018). We conclude that this source is most likely an RSG with an effective temperature in the 3000-4000 K range, matching the classification based on mid-IR photometry presented in Lau et al (2019).…”

Section: Cxou J1403143+541807: An Rsg In Ngc 5457supporting

confidence: 80%

See 1 more Smart Citation

NIR counterparts to ULXs (III): completing the photometric survey and selected spectroscopic results★

López

Heida

Jonker

et al. 2020

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

Abstract We present results from the remaining sources in our search for near-infrared (NIR) candidate counterparts to ultraluminous X-ray sources (ULXs) within ≃ 10 Mpc. We observed 23 ULXs in 15 galaxies and detected NIR candidate counterparts to six of them. Two of these have an absolute magnitude consistent with a single red supergiant (RSG). Three counterparts are too bright for a RSG and spatially extended, and thus we classify them as stellar clusters. The other candidate is too faint for a RSG. Additionally, we present the results of our NIR spectroscopic follow-up of five sources: four originally classified as RSG and one as a stellar cluster on the basis of previous photometry. The stellar cluster candidate is actually a nebula. Of the four RSGs candidates, one source has a broad Hα emission line redshifted by ∼z = 1, making it a background AGN. Two other sources show stellar spectra consistent with them being RSGs. The final RSG candidate is too faint to classify, but does not show strong (nebular) emission lines in its spectrum. After our search for NIR counterparts to 113 ULXs, where we detected a candidate counterpart for 38 ULXs, we have spectroscopically confirmed the nature of 12: five sources are nebulae, one source is not classified, one source is an AGN and five are RSGs. These possible five ULX-RSG binary systems would constitute ≃ $(4 \pm 2)\%$ of the observed ULXs, a fraction almost four times larger than what was predicted by binary evolution simulations.

show abstract

Section: Cxou J1403143+541807: An Rsg In Ngc 5457supporting

confidence: 80%

“…5b). After fitting Gaussian profiles to these lines, we calculated the radial velocity of the source to be 295 ± 16 km s −1 , consistent with the radial velocity of NGC 5457 at the position of the ULX (Hu et al 2018).…”

Section: [Lb2005] Ngc 5457 X26: a Nebulasupporting

confidence: 61%

NIR counterparts to ULXs (III): completing the photometric survey and selected spectroscopic results★

López

Heida

Jonker

et al. 2020

Monthly Notices of the Royal Astronomical Society

View full text Add to dashboard Cite

show abstract

“…First, the degeneracy between q PAH and f abs can be disentangled if either q PAH is determined using MIR spectra observed via MIRI or f abs is derived from MIR photometry based on the empirical estimation of the total IR luminosity (e.g., Boquien et al 2010;Elbaz et al 2010;Lin et al 2016). Furthermore, a combination of these high spatial resolution observations with spectra of H II regions (e.g., Berg et al 2015;Croxall et al 2016;Lin et al 2017;Hu et al 2018) or integral field spectroscopy observations (Sánchez et al 2012) in nearby galaxies will enable us to investigate whether and how the PAH-age relation depends on the local environment at the star cluster scale.…”

Section: Discussionmentioning

confidence: 99%

The Age Dependence of Mid-infrared Emission around Young Star Clusters

Lin

Calzetti

Kong

et al. 2020

ApJ

Self Cite

View full text Add to dashboard Cite

Using the star cluster catalogs from the Hubble Space Telescope program Legacy Extragalactic UV survey (LEGUS) and 8 μm images from the IRAC camera on the Spitzer Space Telescope for five galaxies within 5 Mpc, we investigate how the 8 μm dust luminosity correlates with the stellar age on the 30-50 pc scale of star-forming regions. We construct a sample of 97 regions centered at local peaks of 8 μm emission, each containing one or more young star cluster candidates from the LEGUS catalogs. We find a tight anticorrelation with a Pearson correlation coefficient of r=−0.84±0.05 between the mass-normalized dust-only 8 μm luminosity and the age of stellar clusters younger than 1 Gyr; the 8 μm luminosity decreases with increasing age of the stellar population. Simple assumptions on a combination of stellar and dust emission models reproduce the observed trend. We also explore how the scatter of the observed trend depends on assumptions of stellar metallicity, polycyclic aromatic hydrocarbon (PAH) abundance, fraction of stellar light absorbed by dust, and instantaneous versus continuous star formation models. We find that variations in stellar metallicity have little effect on the scatter, while PAH abundance and the fraction of dust-absorbed light bracket the full range of the data. We also find that the trend is better explained by continuous star formation, rather than instantaneous burst models. We ascribe this result to the presence of multiple star clusters with different ages in many of the regions. Upper limits of the dust-only 8 μm emission as a function of age are provided.

show abstract

“…The Oxygen abundance profile of NGC 5457 shown here, does not show any clear flattening out to 1.2R 25 . However, Hu et al (2018) have found that a flattening is shown at ∼0.8R 25 (consistent with blue curve) when adopting the metallicity indicator from Kobulnicky & Kewley (2004). This serves as a reminder that different methods of measuring Oxygen abundance may play a significant role in determining the detailed features of the profile.…”

Section: The Radial Inflow Rate and Metallicity In Thementioning

confidence: 64%

The Gas-phase Metallicity Profiles of Star-forming Galaxies in the Modified Accretion Disk Framework

Wang,

Lilly

2022

Preprint

Self Cite

View full text Add to dashboard Cite

Simulations indicate that the inflow of gas of star-forming galaxies is almost co-planar and corotating with the gas disk, and that the outflow of gas driven by stellar winds and/or supernova explosions is preferentially perpendicular to the disk. This indicates that the galactic gas disk can be treated as a modified accretion disk. In this work, we focus on the metal enhancement in galactic disks in this scenario of gas accretion. Assuming that the star formation rate surface density (Σ SFR ) is of exponential form, we obtain the analytic solution of gas-phase metallicity with only three free parameters: the scalelength of Σ SFR , the metallicity of the inflowing gas and the mass-loading factor of the wind. According to this simple model, the negative gradient of gas-phase metallicity is a natural consequence of the radial inflow of cold gas which is continuously enriched by in-situ star formation as it moves towards the disk center. We fit the model to the observed metallicity profiles for six nearby galaxies chosen to have well-measured metallicity profiles extending to very large radii. Our model can well characterize the overall features of the observed metallicity profiles. The observed profiles usually show a floor at the outer regions of the disk, corresponding to the metallicity of inflow gas. Furthermore, we find the scalelength of Σ SFR inferred from these fits agree well with independent estimates from the Hα profiles, supporting the basic model.

show abstract

M101: Spectral Observations of H ii Regions and Their Physical Properties

Cited by 19 publications

References 101 publications

NIR counterparts to ULXs (III): completing the photometric survey and selected spectroscopic results★

NIR counterparts to ULXs (III): completing the photometric survey and selected spectroscopic results★

The Age Dependence of Mid-infrared Emission around Young Star Clusters

The Gas-phase Metallicity Profiles of Star-forming Galaxies in the Modified Accretion Disk Framework

Contact Info

Product

Resources

About