New Insights on the Stellar Halos of Massive Galaxies from the HSC Survey
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Massive galaxies are unique for both cosmology and galaxy formation. Here we summarize recent results on the assembly of massive galaxies and their galaxy-halo connections using the deep images from the ambitious Hyper Suprime-Cam Survey.
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in regions very close in projection to the galactic disk. The star-forming regions in the stripped tails
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Star-forming, Hα-emitting clumps are found embedded in the gaseous tails of galaxies undergoing
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unique opportunity to study star formation under extreme conditions, in the absence of an underlying
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velocities of around 320 000 stars drawn from various catalogues, I integrate orbits in a Galactic potential to identify those stars which
come within a few parsecs. Such encounters could influence the solar system, for example through gravitational perturbations of the
Oort cloud. 16 stars are found to come within 2 pc (although a few of these have dubious data). This is fewer than were found in a
similar study based on Hipparcos data, even though the present study has many more candidates. This is partly because I reject stars
with large radial velocity uncertainties (>10 km s−1
), and partly because of missing stars in GDR1 (especially at the bright end). The
closest encounter found is Gl 710, a K dwarf long-known to come close to the Sun in about 1.3 Myr. The Gaia astrometry predict
a much closer passage than pre-Gaia estimates, however: just 16 000 AU (90% confidence interval: 10 000–21 000 AU), which will
bring this star well within the Oort cloud. Using a simple model for the spatial, velocity, and luminosity distributions of stars, together
with an approximation of the observational selection function, I model the incompleteness of this Gaia-based search as a function
of the time and distance of closest approach. Applying this to a subset of the observed encounters (excluding duplicates and stars
with implausibly large velocities), I estimate the rate of stellar encounters within 5 pc averaged over the past and future 5 Myr to be
545±59 Myr−1
. Assuming a quadratic scaling of the rate within some encounter distance (which my model predicts), this corresponds
to 87 ± 9 Myr−1 within 2 pc. A more accurate analysis and assessment will be possible with future Gaia data releases.
EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
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Presentation in the Science Coffee hosted by the Advanced Concepts Team of the European Space Agency on the 12.01.2024.
Speaker: Benoit Famaey (CNRS - Observatoire astronomique de Strasbourg)
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Accretion from Winds of Red Giant Branch Stars May Reveal the Supermassive Bl...
A supermassive black hole (SMBH) of ∼3 × 106 Me was recently detected via dynamical measurements at the
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DYNAMICAL ANALYSIS OF THE DARK MATTER AND CENTRAL BLACK HOLE MASS IN THE DWAR...
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HST imaging of star-forming clumps in 6 GASP ram-pressure stripped galaxies
Exploiting broad- and narrow-band images of the Hubble Space Telescope from near-UV to I-band
restframe, we study the star-forming clumps of six galaxies of the GASP sample undergoing strong
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formed in stripped gas but still close to the disk, called extraplanar. We detect 2406 Hα-selected
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disk and tail clumps, suggesting that the different environments in which they are embedded play a
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HST imaging of star-forming clumps in 6 GASP ram-pressure stripped galaxies
Exploiting broad- and narrow-band images of the Hubble Space Telescope from near-UV to I-band
restframe, we study the star-forming clumps of six galaxies of the GASP sample undergoing strong
ram-pressure stripping (RPS). Clumps are detected in Hα and near-UV, tracing star formation on
different timescales. We consider clumps located in galaxy disks, in the stripped tails and those
formed in stripped gas but still close to the disk, called extraplanar. We detect 2406 Hα-selected
clumps (1708 in disks, 375 in extraplanar regions, and 323 in tails) and 3750 UV-selected clumps (2026
disk clumps, 825 extraplanar clumps and 899 tail clumps). Only ∼ 15% of star-forming clumps are
spatially resolved, meaning that most are smaller than ∼ 140 pc. We study the luminosity and size
distribution functions (LDFs and SDFs, respectively) and the luminosity-size relation. The average
LDF slope is 1.79 ± 0.09, while the average SDF slope is 3.1 ± 0.5. Results suggest the star formation
to be turbulence driven and scale-free, as in main-sequence galaxies. All the clumps, whether they are
in the disks or in the tails, have an enhanced Hα luminosity at a given size, compared to the clumps in
main-sequence galaxies. Indeed, their Hα luminosity is closer to that of clumps in starburst galaxies,
indicating that ram pressure is able to enhance the luminosity. No striking differences are found among
disk and tail clumps, suggesting that the different environments in which they are embedded play a
minor role in influencing the star formation.
HST imaging of star-forming clumps in 6 GASP ram-pressure stripped galaxies
Exploiting broad- and narrow-band images of the Hubble Space Telescope from near-UV to I-band
restframe, we study the star-forming clumps of six galaxies of the GASP sample undergoing strong
ram-pressure stripping (RPS). Clumps are detected in Hα and near-UV, tracing star formation on
different timescales. We consider clumps located in galaxy disks, in the stripped tails and those
formed in stripped gas but still close to the disk, called extraplanar. We detect 2406 Hα-selected
clumps (1708 in disks, 375 in extraplanar regions, and 323 in tails) and 3750 UV-selected clumps (2026
disk clumps, 825 extraplanar clumps and 899 tail clumps). Only ∼ 15% of star-forming clumps are
spatially resolved, meaning that most are smaller than ∼ 140 pc. We study the luminosity and size
distribution functions (LDFs and SDFs, respectively) and the luminosity-size relation. The average
LDF slope is 1.79 ± 0.09, while the average SDF slope is 3.1 ± 0.5. Results suggest the star formation
to be turbulence driven and scale-free, as in main-sequence galaxies. All the clumps, whether they are
in the disks or in the tails, have an enhanced Hα luminosity at a given size, compared to the clumps in
main-sequence galaxies. Indeed, their Hα luminosity is closer to that of clumps in starburst galaxies,
indicating that ram pressure is able to enhance the luminosity. No striking differences are found among
disk and tail clumps, suggesting that the different environments in which they are embedded play a
minor role in influencing the star formation.
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UV and Hα HST observations of 6 GASP jellyfish galaxies
Star-forming, Hα-emitting clumps are found embedded in the gaseous tails of galaxies undergoing
intense ram pressure stripping in galaxy clusters, so-called jellyfish galaxies. These clumps offer a
unique opportunity to study star formation under extreme conditions, in the absence of an underlying
disk and embedded within the hot intracluster medium. Yet, a comprehensive, high spatial resolution
study of these systems is missing. We obtained UVIS/HST data to observe the first statistical sample
of clumps in the tails and disks of six jellyfish galaxies from the GASP survey; we used a combination
of broad-band (UV to I) filters and a narrow-band Hα filter. HST observations are needed to study
the sizes, stellar masses and ages of the clumps and their clustering hierarchy. These observations will
be used to study the clump scaling relations, the universality of the star formation process and verify
whether a disk is irrelevant, as hinted by jellyfish galaxy results. This paper presents the observations,
data reduction strategy, and some general results based on the preliminary data analysis. The UVIS
high spatial resolution gives an unprecedented sharp view of the complex structure of the inner regions
of the galaxies and of the substructures in the galaxy disks. We found clear signatures of stripping
in regions very close in projection to the galactic disk. The star-forming regions in the stripped tails
are extremely bright and compact while we did not detect a significant number of star-forming clumps
outside those detected by MUSE. The paper finally presents the development plan for the project.
UV and Hα HST observations of 6 GASP jellyfish galaxies
Star-forming, Hα-emitting clumps are found embedded in the gaseous tails of galaxies undergoing
intense ram pressure stripping in galaxy clusters, so-called jellyfish galaxies. These clumps offer a
unique opportunity to study star formation under extreme conditions, in the absence of an underlying
disk and embedded within the hot intracluster medium. Yet, a comprehensive, high spatial resolution
study of these systems is missing. We obtained UVIS/HST data to observe the first statistical sample
of clumps in the tails and disks of six jellyfish galaxies from the GASP survey; we used a combination
of broad-band (UV to I) filters and a narrow-band Hα filter. HST observations are needed to study
the sizes, stellar masses and ages of the clumps and their clustering hierarchy. These observations will
be used to study the clump scaling relations, the universality of the star formation process and verify
whether a disk is irrelevant, as hinted by jellyfish galaxy results. This paper presents the observations,
data reduction strategy, and some general results based on the preliminary data analysis. The UVIS
high spatial resolution gives an unprecedented sharp view of the complex structure of the inner regions
of the galaxies and of the substructures in the galaxy disks. We found clear signatures of stripping
in regions very close in projection to the galactic disk. The star-forming regions in the stripped tails
are extremely bright and compact while we did not detect a significant number of star-forming clumps
outside those detected by MUSE. The paper finally presents the development plan for the project.
UV and Hα HST observations of 6 GASP jellyfish galaxies
Star-forming, Hα-emitting clumps are found embedded in the gaseous tails of galaxies undergoing
intense ram pressure stripping in galaxy clusters, so-called jellyfish galaxies. These clumps offer a
unique opportunity to study star formation under extreme conditions, in the absence of an underlying
disk and embedded within the hot intracluster medium. Yet, a comprehensive, high spatial resolution
study of these systems is missing. We obtained UVIS/HST data to observe the first statistical sample
of clumps in the tails and disks of six jellyfish galaxies from the GASP survey; we used a combination
of broad-band (UV to I) filters and a narrow-band Hα filter. HST observations are needed to study
the sizes, stellar masses and ages of the clumps and their clustering hierarchy. These observations will
be used to study the clump scaling relations, the universality of the star formation process and verify
whether a disk is irrelevant, as hinted by jellyfish galaxy results. This paper presents the observations,
data reduction strategy, and some general results based on the preliminary data analysis. The UVIS
high spatial resolution gives an unprecedented sharp view of the complex structure of the inner regions
of the galaxies and of the substructures in the galaxy disks. We found clear signatures of stripping
in regions very close in projection to the galactic disk. The star-forming regions in the stripped tails
are extremely bright and compact while we did not detect a significant number of star-forming clumps
outside those detected by MUSE. The paper finally presents the development plan for the project.
The SAMI Galaxy Sur v ey: galaxy spin is more strongly correlated with stella...
We use the SAMI Galaxy Surv e y to examine the drivers of galaxy spin, λR e , in a multidimensional parameter space including stellar mass, stellar population age (or specific star formation rate), and various environmental metrics (local density, halo mass, satellite versus central). Using a partial correlation analysis, we consistently find that age or specific star formation rate is the primary parameter correlating with spin. Light-weighted age and specific star formation rate are more strongly correlated with spin than mass-weighted age. In fact, across our sample, once the relation between light-weighted age and spin is accounted for, there is no significant residual correlation between spin and mass, or spin and environment. This result is strongly suggestive that the present-day environment only indirectly influences spin, via the removal of gas and star formation quenching. That is, environment affects age, then age affects spin. Older galaxies then have lower spin, either due to stars being born dynamically hotter at high redshift, or due to secular heating. Our results appear to rule out environmentally dependent dynamical heating (e.g. g alaxy–g alaxy interactions) being important, at least within 1 R e where our kinematic measurements are made. The picture is more complex when we only consider high-mass galaxies ( M ∗ ≳ 10 11 M ). While the age-spin relation is still strong for these high-mass galaxies, there is a residual environmental trend with central galaxies preferentially having lower spin, compared to satellites of the same age and mass. We argue that this trend is likely due to central galaxies being a preferred location for mergers.
Exploring the nature and synchronicity of early cluster formation in the Larg...
We analyse Hubble Space Telescope observations of six globular clusters in the Large Magel- lanic Cloud (LMC) from programme GO-14164 in Cycle 23. These are the deepest available observations of the LMC globular cluster population; their uniformity facilitates a precise comparison with globular clusters in the Milky Way. Measuring the magnitude of the main- sequence turn-off point relative to template Galactic globular clusters allows the relative ages of the clusters to be determined with a mean precision of 8.4 per cent, and down to 6 per cent for individual objects. We find that the mean age of our LMC cluster ensemble is identical to the mean age of the oldest metal-poor clusters in the Milky Way halo to 0.2 ± 0.4 Gyr. This provides the most sensitive test to date of the synchronicity of the earliest epoch of globular cluster formation in two independent galaxies. Horizontal branch magnitudes and subdwarf fitting to the main sequence allow us to determine distance estimates for each cluster and examine their geometric distribution in the LMC. Using two different methods, we find an average distance to the LMC of 18.52 ± 0.05.
WHAT CAN WE DEDUCE FROM STUDIES OF NEARBY GALAXY POPULATIONS?
Studies of nearby galaxy populations using large optical surveys like SDSS have provided insights into galaxy formation and evolution. Key findings include identifying characteristic scales where baryon conversion peaks at halo masses of ~10^12 solar masses and galaxies transition from blue to red at stellar masses of ~10^10 solar masses. While surveys have constrained stellar populations and traced dark matter halos, they have not well constrained gas accretion onto galaxies, gas outflows, or the influence of black holes on galaxy evolution.
Stellar-mass black holes in the Hyades star cluster?
Astrophysical models of binary-black hole mergers in the Universe require a significant fraction of stellar-mass black holes (BHs)
to receive negligible natal kicks to explain the gravitational wave detections. This implies that BHs should be retained even in
open clusters with low escape velocities (≲ 1 km/s). We search for signatures of the presence of BHs in the nearest open cluster
to the Sun – the Hyades – by comparing density profiles of direct 𝑁-body models to data from Gaia. The observations are best
reproduced by models with 2−3 BHs at present. Models that never possessed BHs have an half-mass radius ∼ 30% smaller than
the observed value, while those where the last BHs were ejected recently (≲ 150 Myr ago) can still reproduce the density profile.
In 50% of the models hosting BHs, we find BHs with stellar companion(s). Their period distribution peaks at ∼ 103 yr, making
them unlikely to be found through velocity variations. We look for potential BH companions through large Gaia astrometric and
spectroscopic errors, identifying 56 binary candidates - none of which consistent with a massive compact companion. Models
with 2 − 3 BHs have an elevated central velocity dispersion, but observations can not yet discriminate. We conclude that the
present-day structure of the Hyades requires a significant fraction of BHs to receive natal kicks smaller than the escape velocity
of ∼ 3 km s−1
at the time of BH formation and that the nearest BHs to the Sun are in, or near, Hyades.
The completeness-corrected rate of stellar encounters with the Sun from the f...
I report on close encounters of stars to the Sun found in the first Gaia data release (GDR1). Combining Gaia astrometry with radial
velocities of around 320 000 stars drawn from various catalogues, I integrate orbits in a Galactic potential to identify those stars which
come within a few parsecs. Such encounters could influence the solar system, for example through gravitational perturbations of the
Oort cloud. 16 stars are found to come within 2 pc (although a few of these have dubious data). This is fewer than were found in a
similar study based on Hipparcos data, even though the present study has many more candidates. This is partly because I reject stars
with large radial velocity uncertainties (>10 km s−1
), and partly because of missing stars in GDR1 (especially at the bright end). The
closest encounter found is Gl 710, a K dwarf long-known to come close to the Sun in about 1.3 Myr. The Gaia astrometry predict
a much closer passage than pre-Gaia estimates, however: just 16 000 AU (90% confidence interval: 10 000–21 000 AU), which will
bring this star well within the Oort cloud. Using a simple model for the spatial, velocity, and luminosity distributions of stars, together
with an approximation of the observational selection function, I model the incompleteness of this Gaia-based search as a function
of the time and distance of closest approach. Applying this to a subset of the observed encounters (excluding duplicates and stars
with implausibly large velocities), I estimate the rate of stellar encounters within 5 pc averaged over the past and future 5 Myr to be
545±59 Myr−1
. Assuming a quadratic scaling of the rate within some encounter distance (which my model predicts), this corresponds
to 87 ± 9 Myr−1 within 2 pc. A more accurate analysis and assessment will be possible with future Gaia data releases.
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Modelling the Atomic and Molecular Gas in Galaxies and Comparisons wih GASS a...
Modelling the Atomic and Molecular Gas in Galaxies and Comparisons wih GASS a...
Accretion from Winds of Red Giant Branch Stars May Reveal the Supermassive Bl...
Accretion from Winds of Red Giant Branch Stars May Reveal the Supermassive Bl...
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DYNAMICAL ANALYSIS OF THE DARK MATTER AND CENTRAL BLACK HOLE MASS IN THE DWAR...
HST imaging of star-forming clumps in 6 GASP ram-pressure stripped galaxies
HST imaging of star-forming clumps in 6 GASP ram-pressure stripped galaxies
HST imaging of star-forming clumps in 6 GASP ram-pressure stripped galaxies
HST imaging of star-forming clumps in 6 GASP ram-pressure stripped galaxies
HST imaging of star-forming clumps in 6 GASP ram-pressure stripped galaxies
HST imaging of star-forming clumps in 6 GASP ram-pressure stripped galaxies
Evidence for a_massive_extended_circumgalactic_medium_around_the_andromeda_ga...
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UV and Hα HST observations of 6 GASP jellyfish galaxies
UV and Hα HST observations of 6 GASP jellyfish galaxies
UV and Hα HST observations of 6 GASP jellyfish galaxies
UV and Hα HST observations of 6 GASP jellyfish galaxies
UV and Hα HST observations of 6 GASP jellyfish galaxies
UV and Hα HST observations of 6 GASP jellyfish galaxies
The SAMI Galaxy Sur v ey: galaxy spin is more strongly correlated with stella...
The SAMI Galaxy Sur v ey: galaxy spin is more strongly correlated with stella...
Exploring the nature and synchronicity of early cluster formation in the Larg...
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WHAT CAN WE DEDUCE FROM STUDIES OF NEARBY GALAXY POPULATIONS?
WHAT CAN WE DEDUCE FROM STUDIES OF NEARBY GALAXY POPULATIONS?
Stellar-mass black holes in the Hyades star cluster?
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The completeness-corrected rate of stellar encounters with the Sun from the f...
The completeness-corrected rate of stellar encounters with the Sun from the f...
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EWOCS-I: The catalog of X-ray sources in Westerlund 1 from the Extended Weste...
Context. With a mass exceeding several 104 M⊙ and a rich and dense population of massive stars, supermassive young star clusters
represent the most massive star-forming environment that is dominated by the feedback from massive stars and gravitational interactions
among stars.
Aims. In this paper we present the Extended Westerlund 1 and 2 Open Clusters Survey (EWOCS) project, which aims to investigate
the influence of the starburst environment on the formation of stars and planets, and on the evolution of both low and high mass stars.
The primary targets of this project are Westerlund 1 and 2, the closest supermassive star clusters to the Sun.
Methods. The project is based primarily on recent observations conducted with the Chandra and JWST observatories. Specifically,
the Chandra survey of Westerlund 1 consists of 36 new ACIS-I observations, nearly co-pointed, for a total exposure time of 1 Msec.
Additionally, we included 8 archival Chandra/ACIS-S observations. This paper presents the resulting catalog of X-ray sources within
and around Westerlund 1. Sources were detected by combining various existing methods, and photon extraction and source validation
were carried out using the ACIS-Extract software.
Results. The EWOCS X-ray catalog comprises 5963 validated sources out of the 9420 initially provided to ACIS-Extract, reaching a
photon flux threshold of approximately 2 × 10−8 photons cm−2
s
−1
. The X-ray sources exhibit a highly concentrated spatial distribution,
with 1075 sources located within the central 1 arcmin. We have successfully detected X-ray emissions from 126 out of the 166 known
massive stars of the cluster, and we have collected over 71 000 photons from the magnetar CXO J164710.20-455217.
The cost of acquiring information by natural selection
This is a short talk that I gave at the Banff International Research Station workshop on Modeling and Theory in Population Biology. The idea is to try to understand how the burden of natural selection relates to the amount of information that selection puts into the genome.
It's based on the first part of this research paper:
The cost of information acquisition by natural selection
Ryan Seamus McGee, Olivia Kosterlitz, Artem Kaznatcheev, Benjamin Kerr, Carl T. Bergstrom
bioRxiv 2022.07.02.498577; doi: https://doi.org/10.1101/2022.07.02.498577
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Presentation given at the official farewell of Prof Ken Gillet at Wageningen on 13 June 2024
Direct Seeded Rice - Climate Smart Agriculture
Direct Seeded Rice - Climate Smart AgricultureInternational Food Policy Research Institute- South Asia Office
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The binding of cosmological structures by massless topological defects
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equations sourced by a topological defect, i.e. a singularity of a very specific form, the result is a localized gravitational
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spherical shell without any underlying mass. Moreover, a large-scale structure which exploits this solution by assembling
concentrically a number of such topological defects can establish a flat stellar or galactic rotation curve, and can also deflect
light in the same manner as an equipotential (isothermal) sphere. Thus, the need for dark matter or modified gravity theory is
mitigated, at least in part.
ESA/ACT Science Coffee: Diego Blas - Gravitational wave detection with orbita...
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Speaker: Diego Blas (IFAE/ICREA)
Title: Gravitational wave detection with orbital motion of Moon and artificial
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Aleš Zamuda: Randomised Optimisation Algorithms in DAPHNE .
Austrian-Slovenian HPC Meeting 2024 – ASHPC24, Seeblickhotel Grundlsee in Austria, 10–13 June 2024
https://ashpc.eu/
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New Insights on the Stellar Halos of Massive Galaxies from the HSC Survey
- 1. Song Huang 黄崧 (UCSC, Kavli-IPMU https://dr-guangtou.github.io) and the HSC Collaboration 2017.11.02 Princeton New Insights on the Stellar Halos of Massive Galaxies from the HSC survey
- 2. 2 Picture: ESO 325-G004 in Abell S0740 by HST Cover Model for Galaxy Formation since 1998 Picture: Cluster CL1358+62 by HST
- 3. “Compaction”/ Fast Quenching Phase-I: Intense Dissipation Phase-II: Minor/Major Mergers Massive Ellipticals at Low Redshift Inner: Dominated by in situ stars Outer: Dominated by “ex situ” stars in the last 8-10 Gyrs
- 4. 4 Galaxy-Halo Connection at High-M* End Leauthaud et al. (2012)Stellar Mass HaloMass(M200b)M200b/Mstar What’s the best definition of stellar mass to study galaxy-halo connection? Tal et al. (2011) LRGs @ z~0.4 Stacking SDSS images
- 5. 5
- 6. 6 HSC SDSS z~0.19 z~0.30 z~0.37 20” 20” 20” Why Do We Need HSC? • Average i-band seeing 0.6” • i-band surface brightness limit: ~28.5 mag/arcsec2 • Huang et al. (2017c, PASJ Special Issue)
- 7. How does the Assembly of Stellar Halos Depend on Stellar Mass ? Does the Assembly of the Stellar Halo Depend on Dark Matter Halo Mass (Environment) ? Definition and Measurement of Stellar Mass (and its Implications)
- 8. Part I: How does the Assembly of Stellar Halos Depend on Stellar Mass ?
- 9. Photometry of Massive Galaxies using HSC •Large sample of massive galaxies with spectroscopic redshift at 0.3<z<0.5. •Estimate average M/L using 5- band SED fitting (Chabrier IMF). •Empirically correct the background •Build our own pipeline to detect and mask surrounding objects. Huang+ 2017a Mask for Ellipse /399
- 10. 10 PSF 100 kpc Extracting of 1-D Mass Density Profiles We also measure radial profiles for the isophotal shapes Huang+ 2017a
- 11. 11 The scatter is intrinsic! Huang+ 2017a Stellar Halos are NOT Self-Similar
- 12. 12 Redshift Evolution of the Extended Stellar Halo 30 kpc Patel et al. (2013) z~1.4
- 13. 13 Massive BCGs at Redshift = 1.1 140 kpc Liu et al. (2013) XDF
- 14. Rodriguez-Gomez+ (2016) Qu+ 2017 EAGLE FractionofEx-situComponents /3914 Fraction of “Ex-situ” Stars
- 15. D’Souza+ (2014) see also Huang+ (2013) Stacked SDSS images High-concentration Galaxies Based-on 3 Sersic Fitting log(Stellar Mass) However, observational constraints are difficult… Merritt+ (2017) see also Harmsen+ (2017) Dragonfly Nearby Galaxy Survey FractionofOuterComponent Stellar Mass Fraction of “Ex-situ” Stars
- 16. 10 kpc 100 kpc Rodriguez-Gomez+ (2016) Mass within 10 kpc: Proxy of mass formed in-situ at high redshift Mass within 100 kpc: Proxy of the “total stellar mass” Better than cModel and single-Sersic
- 17. FAKE NEWS ! Huang+ 2017a /3917 FractionofExSituStars Similar for Illustris-TNG Pillepich+2017 Fraction of “Ex-situ” Stars
- 18. 18 10 kpc 100 kpc Similar Stellar Mass within 10 Kpc
- 19. Difference in logM100 = 0.5 dex = a factor of 3 Similar Stellar Mass within 10 Kpc
- 20. NO Stacking! Huang+ 2017a /3920 Shape of the Stellar Halo
- 21. 21 Shape of the Stellar Halo Oh et al. (2017) Huang et al. (2013) 2-D Dev+Exp Fitting
- 22. 22 Shape of the Stellar Halo Oblate Prolate Li et al. (2016, 2017)
- 23. 23 Shape of the Stellar Halo Wang et al. (2008) Satellites align with the central galaxy and the dark matter halo Also see Shin et al. (2017); van Uitert et al. (2017); Kang et al. (2007) etc.
- 24. Part II: Does the Stellar Halo Depend on Dark Matter Halo Mass?
- 25. Huertas-Company+2013 Does Size Depend on Environment ? Shankar et al. (2014) Allen et al. (2015) Yes No z ⇠ 0.0 z 0 Nair et al. (2010) Kelkar et al. (2015) Delaye et al. (2014) Papovich et al. (2012) /3925
- 26. Central Galaxies in Cluster-level Halos BCGs of redMaPPer Clusters with λ>30 at 0.3<z<0.5 Rykoff et al. 2014; Rozo et al. 2015 cenHighMh M200c 1.4 ⇥ 1014 M Also see Baxter et al. (2016); Simet et al. (2016) Farahi et al. (2016) RedMaPPer Richness HaloMass(M200c)
- 27. Massive galaxies at 0.3<z<0.5 that are NOT in clusters (Cluster members removed) cenLowMh fSatellites 0.2 van Uitert et al. (2016) Stellar Mass FractionofSatellite Central Galaxies in Less Mass Halos /3927
- 28. Structure v.s. Environment (Halo Mass) Huang+ in prep. Subtle but Systematic Differences Huang+ 2017b Matched in M100 kpc and Redshift /3928
- 29. Mass-Size Relation and Environment Huang+ 2017b More Massive Halos Less Massive Halos /3929
- 30. Much more extended outer halo Huang+ 2017b Matched in M10 kpc and Redshift /3930 Structure v.s. Environment (Halo Mass)
- 31. MHalo, M100 kpc, and M10 kpc Huang+ 2017b More Massive Halos Less Massive Halos /3931
- 32. Red: High Mass Halo Grey: Low Mass Halo MassiveBlack-II MassiveBlack-II Huang+ in prep. Khandai+2015 LOESS Smooth Michelle Cappellari Color Indicates Halo Mass Preliminary MHalo, M100 kpc, and M10 kpc Also see in UniverseMachine (Behroozi+ in prep)
- 33. Part III: Definition and Measurements of Stellar Mass
- 34. Deep 1-D profile is better than CModel or single-Sersic models Huang+ 2017a Does not depend on the SED fitting process /3934 Measurements of “Total” Stellar Mass
- 35. 35 GAMA: Single-Sersic fit to SDSS r-band image Kelvin et al. (2012, 2014) Comparison with Single-Sersic Model
- 36. 11.4 11.6 11.8 12.0 log (M?/M ) (HSC) 6.0 5.5 5.0 4.5 4.0 3.5dN/d?[Mpc3 dex1 ] hscMassive; cModel 11.4 11.6 11.8 12.0 log (M?/M ) (HSC) 6.0 5.5 5.0 4.5 4.0 3.5dN/dlogM?[Mpc3 dex1 ] hscMassive; cModel hscMassive; 100 kpc MassIncomplete /3936 11.4 11.6 11.8 12.0 log (M?/M ) (HSC) 6.0 5.5 5.0 4.5 4.0 3.5dN/dlogM?[Mpc3 dex1 ] hscMassive; cModel hscMassive; 100 kpc hscMassive; Max Additional 0.02-0.05 dex Huang+ 2017a Impacts on Stellar Mass Function
- 37. Huang+ 2017a /3937 Impacts on Stellar Mass Function
- 38. Huang + in prep. Ignore the crazy halo mass value here… Scatter of SHMR Introduced by Mass Measurement
- 39. 39 HSC SDSS 0.19 z~0.30 z~0.37 z~0.44 20” 20” 20”
- 40. Future Directions ❖ Comparison with Hydro-simulations (with Felipe Arbilla) ❖ Intrinsic and observed scatter of SMHR (with Christopher Bradshaw) ❖ Better 2-D photometric models for massive galaxies (with Rajdipa Chowdhury and Dane Cross) ❖ Forward modeling the M100kpc-M10kpc-Mhalo relations with help from the UniverseMachine model (Peter Behroozi, Andrew Hearin) ❖ Better “cluster finder” using just properties of central galaxies ❖ Radial variation of isophote shapes and the intrinsic shape of stellar halos HSC Discussion Next Thursday !
- 41. 41 Thank You Very Much !