Upcoming JC
Title: TBC
Speaker: TBC
Summary:
Past JC
Title: Properties of Barred Galaxies with the Environment: I. the case of the Virgo cluster.
Speaker: Stavros
Summary:
Title: A JWST investigation into the bar fraction at redshifts 1 < z < 3
Speaker: Capucine
Summary: Le Conte et al. analysed galaxies between redshift 1<z<3 in the CANDELS fields, using JWST NIRCam and HST WFC3 imaging, to investigate the presence of bars in disk galaxies at cosmic noon. Using the CEERS observations, they identify the galaxies with photometric redshift in the range of interest, and select the galaxies with good enough spatial resolution for the analysis, bringing the sample to a final number of 768 galaxies. Repeating a similar process with HST imaging of the same regions, they have a sample of 115 HST detected galaxies. The authors then look at the disk fraction in their main sample, through visual inspection of the cutouts by two of the co-authors, and find a disk fraction of about 40%, in line with morphological studies by Ferreira et al. 2023. Finally, they classify the galaxies in both the HST and JWST samples as non-barred, weakly barred or strongly barred; again through visual inspection by five of the co-authors. The analysis is done using the F444W filter for the main sample, and repeated with the F356W filter, with no noticeable change in bar fractions; and is done on the HST sample using the F160W filter. The final bar fractions reported for the JWST sample are 19% in the 1<z<2 range and ~7% in the 2<z<3 range, 3-4 times larger than for the HST sample (results shown in Fig. 6). They find, in line with previous studies, a decreasing trend of the bar fraction with redshift, but that the wavelength chosen for the analysis will impact the results greatly. They also assess that due to the limits in resolution, their results are biased towards larger bars (>2.5-3kpc), and thus their results are most probably lower limits on the bar fraction. Finally, they argue that the amount of bars in galaxies above z=2 points towards a much earlier appearance of bars in disk galaxies than previously thought.
Title: A rest-frame near-IR study of clumps in galaxies at 1 < z < 2 using JWST/NIRCam: connection to galaxy bulges
Speaker: Claudia
Summary: See here
Title: First spectroscopic observations of the galaxies that reionized the Universe
Speaker: Jean-Baptiste
Summary:
In this paper the authors present the spectroscopic analysis of 8 ultra-faint lensed galaxies at 6<z<8, using a combination of HST, JWST imaging (NIRCam, from the UNCOVER survey), and deep NIRSPec spectroscopy (also from UNCOVER). Given the high magnification and long integration then manage to reach unprecedentedly faint magnitudes. Using mostly the Halpha line they compute the ionizing efficiency of the faint population at the epoch of reionization. Combined with a computation of the UV photons density they show that a low escape fraction of 5% could be sufficient to ionize the universe, and that faint galaxies (i.e. the bulk of the galaxy population) are prodigous producer of ionizing photons. According to them this shows that faint galaxies were the main drivers of cosmic reionization.
Title: Are "Changing-Look'' Active Galactic Nuclei Special in the Coevolution of Supermassive Black Holes and their Hosts? I
Speaker: Daryl
Summary:
Title: Exploring the Impact of Galactic Interactions and Mergers on the Central Star Formation of APEX/EDGE-CALIFA Galaxies
Speaker: Yixian
Summary:
This study compared 110 interacting galaxies with 126 isolated galaxies with IFU + CO observations of central ~1Re of local galaxies.
They found that the gas fraction increases in the interacting galaxies compared to the isolated galaxies in their sample, but SFE and sSFR do not increase.
They compared the relative importance of gas fraction and SFE in each sSFR bin, and concluded that in most of cases in interacting galaxies, changes in SFE is more likely the main driver for the variations of sSFR.
Title: Stellar Half-Mass Radii of 0.5<z<2.3 Galaxies: Comparison with JWST/NIRCam Half-Light Radii.
Speaker: Lilian
Summary:
This paper:
Introduces a method to estimate stellar half-mass radii for galaxies at 0.5 < z < 2.5, utilising integrated UV-to-midIR photometric data.
Validates the method by comparing their estimates with measurements from JWST/NIRCam imaging for a subset of CEERS galaxies, showing excellent agreement with small systematic offsets and scatter within the error budget.
Examines the effect of projection using a deprojection technique that considers the shape distribution of galaxies, their dependencies on stellar mass and redshift, and concludes that deprojection has little impact on the size-mass distribution.
Reveals that the size-mass distribution of galaxies at 0.5 < z < 1.5 is less steep in the rest-frame optical than previously believed, primarily due to the influence of massive star-forming galaxies.
Offers a straightforward conversion from light-to-stellar mass-weighted sizes, making it valuable for galaxies lacking spatially resolved near-IR imaging or at high z.
Acknowledges uncertainties in small galaxies, challenging due to limited understanding of the near-IR PSF of NIRCam.
Title: Composite Bulges -- IV. Detecting Signatures of Gas Inflows in the IFU data: The MUSE View of Ionized Gas Kinematics in NGC 1097
Speaker: Shangguan
Summary: This paper analyze the detailed kinematic features of MUSE data cube of the inner starburst ring of NGC 1097. They emphasize the difficulties of reviewing the inflow features by simply comparing the gas velocity map with the circular disk model, due to both the uncertainties of the prior information of the PA and inclination and the presumably complex kinematics of the gas dynamics. Then, they discuss the evidence of the physical origin of some coherent velocity map residual patterns with BPT diagram and advertise that the velocity difference between [NII] and Halpha lines can be a useful indicator of the shocked region of the inflow gas. Overall, this work focuses on very small scale gas kinematic structures comparing to the studies of high-z galaxies of our group.
Title: Statistics for Galaxy Outflows at z∼6−9 with Imaging and Spectroscopic Signatures Identified with JWST/NIRCam and NIRSpec Data
Speaker: Capucine
Summary: Zhang et al look at 61 galaxies between z=5.4 and 8.9, both using NIRSpec spectroscopy and NIRCam imaging, to study the outflow properties in their sample. They make a study of both spatially extended [OIII] emission in the imaging (5/61) and broad component in the emission line, indicating the presence of fast winds (5/30); including one galaxy that has both spatially extended emission and a broad component in the spectra. They compute the ratio of the wind velocity over the escape velocity of the galaxies' halo, and find that none of the detected outflows have velocities high enough to eject gas outside the gravitational well of the halo. They conjecture that they are witnessing the different phases of a star forming outflow event (as shown in the figure, where in the beginning outflows can only be seen in the spectra, then an extended emission is observed, and finally it falls back into the galaxy). They also compare their outflow incidence in the extended emission at high redshift to local studies, and find an increase in the incidence broadly consistent with the increase in major merger rate; but fail to observe a similar increase in incidence with the "spectral" outflows (Figure 11).
Title: The MOSDEF-LRIS Survey: Detection of Inflowing Gas Towards Three Star-forming Galaxies at z ~ 2
Speaker: Daizhong
Summary: The authors observed wide rest-UV absorption lines in three MOSDEF galaxies. They argue that these are the signature of inflowing gas from the recycled metal-enriched gas with a large velocity ~250-500 km/s, instead of pristine gas from the CGM.
Meeting location: MPE IR meeting room and mpeir Zoom (passcode: 123)
Date and time: Every Monday at 13h45
Q&A:
Q: Where should I look for or suggest papers?
A: MPE IR Benty-fields or in the MPE IR Group Slack channel #galev-interesting-papers
Q: What if I do not have access to MPE IR Benty-fields page or the Slack channel?
A: Send an email to Lilian (lilian[at]mpe.mpg.de)
This page is maintained by Lai Yee Lilian Lee and Claudia Pulsoni . Last updated on 4 Oct 2023.
