The-9th-c-manga-workshop:abstracts

The 9th C-MaNGA workshop, SHAO, June 21-22, 2018

Abstract Submission

Provide the requested information if you are going to give a talk at the meeting. Please follow the same format as the example (keep the example on the top and don't delete it!).

Example

• Title: A summary of the MaNGA science projects at Tsinghua

Speaker: Cheng Li

Abstract: I will summarize the ongoing MaNGA projects at Tsinghua.

Please submit your abstract before Jun. 15, 2019.

Submitted Abstracts

• Title: Distribution of stellar dust in MaNGA galaxies

Speaker: Cheng Li

Abstract: I will present an ongoing MaNGA project led by a student at Tsinghua, Xiaoya Zhang who has been examining the maps/profiles of E(B-V) obtained by Niu Li and dependence on galaxy properties. I will summarize the results so far.

• Title: Environmental dependence of star-formation quenching in low-z galaxies

Speaker: Wen Shi

Abstract: I will present a new analysis of the environment of MaNGA galaxies, examining the correlation of star formation cessation in MaNGA galaxies as indicated by D4000, EW(Halpha) and EW(Hdelta_A) with their environment. For environment we consider the central/satellite division, the local density and the host dark matter halo mass. I will show that central and satellite galaxies show different quenching status even when stellar mass and halo mass are limited to a narrow range.

• Title: Galaxies with debris of merger in MaNGA

Speaker: Songlin Li

Abstract: We crossmatch the galaxies in MaNGA MPL-8 with the Legacy Survey, which provides both g and r band images about one magnitude deeper than those in SDSS. We find 550 galaxies with debris of merger(tidal tails, shells, asymmetric halo or distorted feature with companions). In this sample, we find overall higher star formation rate(SFR) and higher stellar mass comparing with whole MaNGA sample. Moreover, there is a higher possibility for those galaxies with gas-stellar rotating misalignment to contain those debris of merger, while we don't see significant differences of the possibility between co-rotation and counter-rotation. This result corroborates the influence of merger on gas-stellar misalignment and supports the gas precession scenario, a scenario that external misaligned gas could precess to either co-rotation or counter-rotation with in situ stellar due to gravitational dynamical settling.

• Title: Where does the star formation in galaxies peak?

Speaker: Shiyin Shen

Abstract: We develop a new algorithm to identify the HII regions on the Ha maps of MaNGA galaxies. We will take the advantages of the large MaNGA galaxy sample and explore the statistical properties of these HII regions.

• Title: Kinematic Field of Ionized Gas in Galaxy Pairs

Speaker: Shuai Feng

Abstract: We explore the kinematic field of ionized gas for galaxy pairs. We find the fraction of non-circular components of the kinematic field increase with decreasing projected separation. For the galaxy pair with a higher fraction of non-circular components, their SFR is significant enhanced than the control sample. While for the other galaxy pair (lower fraction of non-circular components), their SFR shows little enhancement.

• The stellar mass-metallicity relation of pair galaxies

Speaker: Zhai Sai

Abstarct: We utilize Mapping Nearby Galaxies at Apache Point Observatory integral field spectroscopy of star-forming region of 5592 galaxies to study the relation between stellar mass and gas-phase metallicity. We stack the spectra from 1 effective radius(Re) to 1.5Re ofper galaxyand obtain emissionlines by fittingwith Penalized Pixel-Fitting(pPXF). We derive gas phase abundances using indicators that make use of photoionization models-KD02 or combine the empirical and theoretical models-Do2. Stellar masses are derived by spectral energy distribution(SED) fitting from GSWLC. We find that the galaxy with larger stellar mass contains more metal. All the pairs in the sample are selected by using two classification criteria. The separation are required to be r<60 kpc (or 150 kpc), the velocity separation are required to be Δv < 500 km/s (or 1000 km/s). Comparing with randomly selected isolated galaxies, no clear evidence shows that the Circumgalactic medium effects the metallicity distribution of pair galaxies.

• The internal orbital structures of early-type galaxies and its dependence with environment

Speaker: Ling Zhu

Abstarct: We apply orbital superposition Schwarzschild method to 149 ETGs in the mass range of 109.86 1011.61M⊙ selected from the integral-field survey Mapping Nearby Galaxies with APO (MaNGA). These galaxies are classified to be 105 central and 44 satellite galaxies based on the group catalog from Yang et al. (2007). We find that low-mass galaxies with log(M∗/M⊙) < 10.9 have an average dark matter fraction of ∼ 0.2 within one effective radii Re, tend to be oblate-like, and are dominated by minor-axis rotations. High-mass galaxies with log(M∗/M⊙) > 10.9 have an average dark matter fraction of ∼ 0.4 within one effective radii Re, tend to be prolate-like, and are dominated by major-axis rotations and random motions. The change of internal structures within Re are dominated by the total stellar mass of the galaxies, and there is no difference between centrals and satellites with control of stellar mass. However, the galaxies more triaxial or with higher hot orbit fractions do have more close neighbors with $rp < 30$ kpc.

• A catalog of Wolf-Rayet galaxies in MaNGA and relevant scientific analysis

Speaker: Fuheng Liang

Abstract: Wolf-Rayet (WR) galaxies are defined as galaxies presenting broad emission lines of He/C/N in their spectra. This reflects the existence of WR stars, a population of very massive and short-lived stars (<10 Myr). We intend to use WR galaxies in MaNGA for constraining the initial mass function. The catalog consists of 90 WR galaxies containing 260 WR regions. We have finished analyzing most of the host galaxy properties such as mass-metallicity relation. We have also carried out spatially resolved analysis and WR feature fitting. We will present the catalog and the analysis so far.

• Bayesian Analysis of the star formation history of low-mass galaxies in MaNGA

Speaker: Shuang Zhou

Abstract: As the smallest, least luminous, however most common systems in the universe, dwarf galaxies have come to play an increasingly important role in understanding how galaxies form and evolve.We use a Bayesian inference code to analyze the IFU data-cubes of low mass galaxies in MaNGA, aiming to examine the star formation history of those galaxies. We focus on whether we can find hints of the hidden old stellar population in the low mass dwarfs, how the assumed SFH model would bias the inference of stellar properties, and how the SFHs vary within a single galaxy and between different galaxies.

• Dust attenuation and star formation in galaxy mergers

Speaker: Fangting Yuan

Abstract: We investigate the dust attenuation in galaxy mergers using the multiwavelength photometry from the ultraviolet (UV) to the infrared (IR), and MaNGA's integral field spectroscopy. Comparing the dust attenuation derived from the UV-to-IR data and the optical data, we find that the difference is consistent with the picture that younger stellar populations are attenuated by an additional dust component from the birth clouds compared to older stellar populations which are only attenuated by the diffuse dust. Our results suggest that the two-component dust model is more robust to reconstruct the SFH of the galaxy merger than the simple one-component dust model.

• Constructing a galaxy sample with molecular gas information at sub-galactic resolution

Speaker: Ruonan Guo

Abstract: We collate and summarize the observed galaxies of ALMA telescope, and establish a galaxy molecular gas sample with pretty high resolution. Then matching it with the existing MaNGA and Herschel Galaxy catalogues to find the same galaxies included in all three catalogues for subsequent multi-wavelength research. By sorting and marching, there are 133 galaxies with both ALMA and Herschel observations, and 29 with both ALMA and Sloan/MaNGA observations. The merging galaxy NGC2623 is found to have observations in all 3 bands.

• Dust distribution in disk galaxies

Speaker: Niu Li

Abstract: Based on the two-dimensiontal distribution of dust in disk galaxies, we have started with a sample of face-on galaxies, obtaining their E(B-V) maps/profiles and attempt to reconstruct their 3D dust distribution. Preliminary results will be presented.

• Dust geometry in nearby disk galaxies

Speaker: Jiafeng Lu

By analyse spectrum of 150000 disk galaxies in SDSS, we find a difference between extinction of emission and extinction of continuum. Then we give a quantitative estimation of dust geometry to explain it. We also check the rationality of our conclusions with MaNGA data.