Attenuation Modified by DIG and Dust as Seen in M31

Tomičić, Neven; Kreckel, Kathryn; Groves, Brent; Schinnerer, E.; Sandström, Karin; Kapala, Maria; Blanc, Guillermo A.; Leroy, Adam K.

doi:10.3847/1538-4357/aa7b30

Cited by 18 publications

(19 citation statements)

References 111 publications

(191 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…However, this prescription may differ given the small spatial scales probed in M31 (Faesi et al 2014). In our previous paper, Tomičić et al (2017), we found that the dust/gas distribution in M31 mostly follows the foreground screen models, and that the dust scale height is larger than the scale height of the DIG and HII regions for our studied fields. Therefore, in the following calculation, we will also assume a simple screen model of the dust/gas distribution, use the CCM extinction curve, the Balmer decrement of Hα/Hβ=2.86, and the selective extinction with R V =3.1 (Kreckel et al 2013, Tomičić et al 2017).…”

Section: Conversion From Hα and Fuv To Sfrsupporting

confidence: 53%

“…M31 is a highly inclined galaxy, and the fields used in this paper probe galactocentric radii that are larger than the galaxies (KINGFISH, SINGS and CALIFA surveys, and NGC 3627, NGC 628) used for calibration of the SFR prescriptions in the literature. This leads to higher attenuation for the same dust mass surface density compared to nearby galaxies (Tomičić et al 2017), and larger a IR and b IR factors. Due to the large galactocentric distance, the M31 field also have a low surface brightness in the mid-IR and observed Halpha emission (Fig.…”

Section: Galactocentric Radius and Inclinationmentioning

confidence: 99%

“…The optical IFU spectral data in this work were previously used by Kapala et al (2015), Kapala et al (2017) and Tomičić et al (2017) as a part of the Survey of Lines in M31 (SLIM) project. The observation and calibration of the data and the derivation of Balmer emission lines are described in detail in Kreckel et al (2013); Kapala et al (2015); Tomičić et al (2017). Here we only provide a short summary.…”

Section: Optical Hα Datamentioning

confidence: 99%

“…Analyzing the same M31 fields, Tomičić et al (2017) concluded that the vertical distribution of the dust and ionized gas must change differently as a function of galactocentric distance in order to explain why the measured attenuation in the outskirts of M31 is higher than the measured attenuation in the central regions of nearby galaxies. If we assume that the dust is well mixed with the HI and H 2 gas (Holwerda et al 2012;Hughes et al 2014), the vertical scale-height of the dust should increase with a galactocentric radius as both HI and H 2 gas layers are thickening towards the outer disk (as seen for the highly inclined M31 and other galaxies ;Braun 1991;Olling 1996;Yim et al 2014).…”

Section: Galactocentric Radius and Inclinationmentioning

confidence: 99%

See 3 more Smart Citations

Calibrating Star Formation Rate Prescriptions at Different Scales (10 pc–1 kpc) in M31

Tomičić

Kreckel

et al. 2019

ApJ

Self Cite

View full text Add to dashboard Cite

We calibrate commonly used star formation rate (SFR) prescriptions using observations in five kpcsized fields in the nearby galaxy Andromeda (M31) at 10 pc spatial resolution. Our observations at different scales enable us to resolve the star-forming regions and to distinguish them from non starforming components. We use extinction corrected Hα from optical integral field spectroscopy as our reference tracer and have verified its reliability via tests. It is used to calibrate monochromatic and hybrid (Hα+a×IR and FUV+b×IR) SFR prescriptions, which use FUV (GALEX), 22 µm (WISE) and 24 µm (MIPS). Additionally, we evaluate other multi-wavelength infra-red tracers. Our results indicate that the SFR prescriptions do not change (in M31) with spatial scales or with subtraction of the diffuse component. For the calibration factors in the hybrid SFR prescriptions, we find a≈0.2 and b≈22 in M31, which are a factor of 5 higher than in the literature. As the fields in M31 exhibit high attenuation and low dust temperatures, lie at large galacto-centric distances, and suffer from high galactic inclination compared to measurements in other galaxies, we propose that the fields probe a dust layer extended along the line of sight that is not directly spatially associated with star-forming regions. This (vertically) extended dust component increases the attenuation and alters the SFR prescriptions in M31 compared to literature measurements. We recommend that SFR prescriptions should be applied with caution at large galacto-centric distances and in highly inclined galaxies, due to variations in the relative (vertical) distribution of dust and gas. Subject headings: galaxies: ISM -galaxies: individual (M31) -galaxies: star formation -ISM: HII regions 2 R 25 is the radius at which the observed optical intensity is equal to 25 mag in the B band.3 Polycyclic aromatic hydrocarbon molecules.

show abstract

Section: Conversion From Hα and Fuv To Sfrsupporting

confidence: 53%

Section: Galactocentric Radius and Inclinationmentioning

confidence: 99%

Section: Optical Hα Datamentioning

confidence: 99%

Section: Galactocentric Radius and Inclinationmentioning

confidence: 99%

See 2 more Smart Citations

Calibrating Star Formation Rate Prescriptions at Different Scales (10 pc–1 kpc) in M31

Tomičić

Kreckel

et al. 2019

ApJ

Self Cite

View full text Add to dashboard Cite

show abstract

“…The trend is largely driven by the physical characteristics of the ISM such as gas-phase metallicity and ionization parameter which may vary across a galaxy (e.g. Tomičić et al 2017).…”

Section: Extinction Correctionmentioning

confidence: 99%

The effects of diffuse ionized gas and spatial resolution on metallicity gradients: TYPHOON two-dimensional spectrophotometry of M83

Poetrodjojo

D'Agostino

Groves

et al. 2019

Monthly Notices of the Royal Astronomical Society

Self Cite

View full text Add to dashboard Cite

We present a systematic study of the diffuse ionized gas (DIG) in M83 and its effects on the measurement of metallicity gradients at varying resolution scales. Using spectrophotometric data cubes of M83 obtained at the 2.5m duPont telescope at Las Campanas Observatory as part of the TYPHOON program, we separate the Hii regions from the DIG using the [SII]/Hα ratio, HIIphot (Hii finding algorithm) and the Hα surface brightness. We find that the contribution to the overall Hα luminosity is approximately equal for the Hii and DIG regions. The data is then rebinned to simulate low-resolution observations at varying resolution scales from 41 pc up to 1005 pc. Metallicity gradients are measured using five different metallicity diagnostics at each resolution. We find that all metallicity diagnostics used are affected by the inclusion of DIG to varying degrees. We discuss the reasons of why the metallicity gradients are significantly affected by DIG using the Hii dominance and emission line ratio radial profiles. We find that applying the [SII]/Hα cut will provide a closer estimate of the true metallicity gradient up to a resolution of 1005 pc for all metallicity diagnostics used in this study.

show abstract

MUSE crowded field 3D spectroscopy in NGC 300

Micheva

Roth

Weilbacher

et al. 2022

A&A

View full text Add to dashboard Cite

Context. There are known differences between the physical properties of H ii and diffuse ionized gas (DIG). However, most of the studied regions in the literature are relatively bright, with log 10 L(Hα)[erg/s] 37. Aims. We compiled an extremely faint sample of 390 H ii regions with a median Hα luminosity of 34.7 in the flocculent spiral galaxy NGC 300, derived their physical properties in terms of metallicity, density, extinction, and kinematics, and performed a comparative analysis of the properties of the DIG. Methods. We used MUSE data of nine fields in NGC 300, covering a galactocentric distance of zero to ∼ 450 arcsec (∼ 4 projected kpc), including spiral arm and inter-arm regions. We binned the data in dendrogram leaves and extracted all strong nebular emission lines. We identified H ii and DIG regions and compared their electron densities, metallicity, extinction, and kinematic properties. We also tested the effectiveness of unsupervised machine-learning algorithms in distinguishing between the H ii and DIG regions. Results. The gas density in the H ii and DIG regions is close to the low-density limit in all fields. The average velocity dispersion in the DIG is higher than in the H ii regions, which can be explained by the DIG being 1.8 kK hotter than H ii gas. The DIG manifests a lower ionization parameter than H ii gas, and the DIG fractions vary between 15-77%, with strong evidence of a contribution by hot low-mass evolved stars and shocks to the DIG ionization. Most of the DIG is consistent with no extinction and an oxygen metallicity that is indistinguishable from that of the H ii gas. We observe a flat metallicity profile in the central region of NGC 300, without a sign of a gradient. Conclusions. The differences between extremely faint H ii and DIG regions follow the same trends and correlations as their much brighter cousins. Both types of objects are so heterogeneous, however, that the differences within each class are larger than the differences between the two classes.

show abstract

Attenuation Modified by DIG and Dust as Seen in M31

Cited by 18 publications

References 111 publications

Calibrating Star Formation Rate Prescriptions at Different Scales (10 pc–1 kpc) in M31

Calibrating Star Formation Rate Prescriptions at Different Scales (10 pc–1 kpc) in M31

The effects of diffuse ionized gas and spatial resolution on metallicity gradients: TYPHOON two-dimensional spectrophotometry of M83

MUSE crowded field 3D spectroscopy in NGC 300

Contact Info

Product

Resources

About