Mass-segregation trends in SDSS galaxy groups

Roberts, Ian; Parker, Laura C.; Joshi, Gandhali D.; Evans, Fraser A.

doi:10.1093/mnrasl/slu188

Cited by 28 publications

(43 citation statements)

References 39 publications

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“…At R ∼ 20 kpc (i.e., the smallest scales probed), the correction is 20-30 per cent and is negligible at R ∼ 50 kpc. We find that on average c t is approximately independent of cluster-centric distance, because there is no strong luminosity segregation of galaxies in clusters as massive as those in MENeaCS (e.g., Roberts et al 2015). For reference, a fraction of order 10 −6 lens-source pairs have |c t | > 0.01, which corresponds to the typical shear produced by massive cluster galaxies in our sample.…”

Section: Additive Shear Biasmentioning

confidence: 67%

The galaxy–subhalo connection in low-redshift galaxy clusters from weak gravitational lensing

Sifón

Herbonnet

Hoekstra

et al. 2018

Monthly Notices of the Royal Astronomical Society

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We measure the gravitational lensing signal around satellite galaxies in a sample of galaxy clusters at z < 0.15 by combining high-quality imaging data from the Canada-France-Hawaii Telescope with a large sample of spectroscopically-confirmed cluster members. We use extensive image simulations to assess the accuracy of shape measurements of faint, background sources in the vicinity of bright satellite galaxies. We find a small but significant bias, as light from the lenses makes the shapes of background galaxies appear radially aligned with the lens. We account for this bias by applying a correction that depends on both lens size and magnitude. We also correct for contamination of the source sample by cluster members. We use a physically-motivated definition of subhalo mass, namely the mass bound to the subhalo, m bg , similar to definitions used by common subhalo finders in numerical simulations. Binning the satellites by stellar mass we provide a direct measurement of the subhalo-to-stellar-mass relation, log m bg /M = (11.54 ± 0.05) + (0.95 ± 0.10) log[m /(2 × 10 10 M )]. This best-fitting relation implies that, at a stellar mass m ∼ 3 × 10 10 M , subhalo masses are roughly 50 per cent of those of central galaxies, and this fraction decreases at higher stellar masses. We find some evidence for a sharp change in the total-to-stellar mass ratio around the clusters' scale radius, which could be interpreted as galaxies within the scale radius having suffered more strongly from tidal stripping, but remain cautious regarding this interpretation.

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Section: Additive Shear Biasmentioning

confidence: 67%

The galaxy–subhalo connection in low-redshift galaxy clusters from weak gravitational lensing

Sifón

Herbonnet

Hoekstra

et al. 2018

Monthly Notices of the Royal Astronomical Society

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“…We find with 99.1% confidence that the samples do not have the same radial distribution. The difference in central concentration may reflect mass segregation, with more massive galaxies in a cluster or group being more centrally concentrated (Presotto et al 2012;Roberts et al 2015). Plausible physical reasons for that apparent concentration range from environmentally dependent formation histories, differences in dynamical friction, or mass-dependent tidal stripping.…”

Section: The Ngc 2784 Galaxy Groupmentioning

confidence: 99%

Dwarf Galaxy Discoveries from the KMTNet Supernova Program. I. The NGC 2784 Galaxy Group^*

Park

Moon

Zaritsky

et al. 2017

ApJ

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We present BV I surface photometry of 31 dwarf galaxy candidates discovered in a deep image stack from the KMTNet Supernova Program of ∼ 30 square degrees centered on the nearby NGC 2784 galaxy group. Our final images have a 3σ surface brightness detection limit of µ V ≈ 28.5 mag arcsec −2 . The faintest central surface brightness that we measure is µ 0,V = 26.1 mag arcsec −2 . If these candidates are at the distance of NGC 2784, then they have absolute magnitudes greater than M V = −9.5 mag and effective radii larger than 170 pc. Their radial number density decreases exponentially with distance from the center of NGC 2784 until it flattens beyond a radius of 0.5 Mpc. We interpret the baseline density level to represent the background contamination and so estimate that 22 of the 31 new candidates are dwarf members of the group. The candidate's average color, (B − V ) 0 ≈ 0.7, and Sérsic structural parameters are consistent with those parameters for the dwarf populations of other groups. We find that the central population of dwarfs is redder and brighter than the rest of the population. The measured faint end slope of the luminosity function, α ≈ −1.33, is steeper than that of the Local Group but consistent with published results for other groups. Such comparisons are complicated by systematic differences among different studies, but will be simpler when the KMTNet survey, which will provide homogenous data for 15 to 20 groups, is completed.

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“…Since the segregation results for the DM-halo masses of the galaxies are stronger when low mass galaxies are included, we wanted to determine if the lower mass cut would affect the stellar mass results in the same way. We compare our results to observational results from Roberts et al (2015), shown in black; while their sample is complete and unweighted in (a), it is Vmax weighted in (b) to correct for incompleteness. The mass limits on the host haloes are identical between our results and the observational results.…”

Section: Comparing Mz=0 and M Peakmentioning

confidence: 99%

“…The errors shown are standard errors on the mean. Note that we use r vir instead of R 200 and our positions are 3-D while those in Roberts et al (2015) are projected.…”

Section: Comparing Mz=0 and M Peakmentioning

confidence: 99%

“…van den Bosch et al (2008) found segregation in stellar mass using data from the SDSS-DR7 (Abazajian et al 2009) and concluded that the trends were a result of mass segregation and correlations between stellar mass and colour/concentration. More recently, Roberts et al (2015) found weak stellar mass segregation in galaxy groups in the SDSS-DR7. They also found that the segregation trends were stronger when low mass galaxies were included and that the trends were weaker in higher mass groups/clusters.…”

Section: Introductionmentioning

confidence: 97%

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Preprocessing, mass-loss and mass segregation of galaxies in dark matter simulations

Joshi¹,

Wadsley²,

Parker³

2017

Monthly Notices of the Royal Astronomical Society

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We investigate the mass loss of galaxies in groups and clusters with high-resolution DM simulations. We detect weak mass segregation in the inner regions of group/cluster haloes, consistent with observational findings. This applies to samples of galaxy analogues selected using either their present-day mass or past maximum (peak) mass. We find a strong radial trend in the fractional mass lost by the galaxies since peak, independent of their mass. This suggests that segregation is due to massive galaxies having formed closer to the halo centres and not the preferential destruction of smaller galaxies near halo centres. We divide our sample into galaxies that were accreted as a group vs. as a single, distinct halo. We find strong evidence for preprocessing -the grouped galaxies lose ∼ 35 − 45% of their peak mass before being accreted onto their final host haloes, compared to single galaxies which lose ∼ 12%. After accretion, however, the single galaxies lose more mass compared to the grouped ones. These results are consistent with a scenario in which grouped galaxies are preprocessed in smaller haloes while single galaxies 'catch up' in terms of total mass loss once they are accreted onto the final host halo. The fractional mass loss is mostly independent of the galaxy mass and host mass, and increases with amount of time spent in a dense environment.

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Mass-segregation trends in SDSS galaxy groups

Cited by 28 publications

References 39 publications

The galaxy–subhalo connection in low-redshift galaxy clusters from weak gravitational lensing

The galaxy–subhalo connection in low-redshift galaxy clusters from weak gravitational lensing

Dwarf Galaxy Discoveries from the KMTNet Supernova Program. I. The NGC 2784 Galaxy Group^*

Preprocessing, mass-loss and mass segregation of galaxies in dark matter simulations

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Mass-segregation trends in SDSS galaxy groups

Cited by 28 publications

References 39 publications

The galaxy–subhalo connection in low-redshift galaxy clusters from weak gravitational lensing

The galaxy–subhalo connection in low-redshift galaxy clusters from weak gravitational lensing

Dwarf Galaxy Discoveries from the KMTNet Supernova Program. I. The NGC 2784 Galaxy Group*

Preprocessing, mass-loss and mass segregation of galaxies in dark matter simulations

Contact Info

Product

Resources

About

Dwarf Galaxy Discoveries from the KMTNet Supernova Program. I. The NGC 2784 Galaxy Group^*