325 research outputs found
The stellar halos of ETGs in the IllustrisTNG simulations: the photometric and kinematic diversity of galaxies at large radii
We characterize the photometric and kinematic properties of simulated
early-type galaxy (ETG) stellar halos, and compare them to observations. We
select a sample of ~1200 ETGs in the TNG100 and TNG50 simulations, spanning a
stellar mass range of and within the range of
(g-r) colour and lambda-ellipticity diagram populated by observed ETGs. We
determine photometric parameters, intrinsic shapes, and kinematic observables
in their extended stellar halos. We study the variation in kinematics from
center to halo and connect it to a change in the intrinsic shape of the
galaxies. We find that the simulated galaxy sample reproduces the diversity of
kinematic properties observed in ETG halos. Simulated fast rotators (FRs)
divide almost evenly in one third having flat lambda profiles and high halo
rotational support, a third with gently decreasing profiles, and another third
with low halo rotation. Slow rotators (SRs) tend to have increased rotation in
the outskirts, with half of them exceeding lambda=0.2. For
halo rotation is unimportant. A similar variety of
properties is found for the stellar halo intrinsic shapes. Rotational support
and shape are deeply related: the kinematic transition to lower rotational
support is accompanied by a change towards rounder intrinsic shape. Triaxiality
in the halos of FRs increases outwards and with stellar mass. Simulated SRs
have relatively constant triaxiality profiles. Simulated stellar halos show a
large variety of structural properties, with quantitative but no clear
qualitative differences between FRs and SRs. At the same stellar mass, stellar
halo properties show a gradual transition and significant overlap between the
two families, despite the clear bimodality in the central regions. This is in
agreement with observations of extended photometry and kinematics. [abridged]Comment: accepted for publication in A&A, 25 pages, 22 figure
The stellar halos of ETGs in the IllustrisTNG simulations: II. Accretion, merger history, and dark halo connection
Stellar halos in early-type galaxies (ETGs) are shaped by their accretion and
merger histories. We use a sample of 1114 ETGs in the TNG100 simulation with
stellar masses , selected at z=0
within the range of g-r colour and lambda-ellipticity diagram populated by
observed ETGs. We study how the rotational support and intrinsic shapes of the
stellar halos depend on the fraction of stars accreted, overall and separately
by major, minor, and mini mergers. Accretion histories in TNG100 ETGs as well
as the radial distributions of ex-situ stars strongly correlate
with stellar mass. Low-mass ETGs have characteristic peaked rotation profiles
and near-oblate shapes with rounder halos that are completely driven by the
in-situ stars. At high major mergers decrease the in-situ peak in
rotation velocity, flatten the profiles, and increase the
triaxiality of the stellar halos. Kinematic transition radii do not trace the
transition between in-situ and ex-situ dominated regions, but for systems with
the local rotational support and triaxiality of the
stellar halos is anti-correlated with the local ex-situ fraction at
fixed . These correlations are followed by fast and slow rotators alike
with a continuous and overlapping sequence of properties. Merger events
dynamically couple stars and dark matter: in high mass ETGs and at large radii
where , both components tend to have similar intrinsic shapes
and rotational support, and nearly aligned principal axes and spin directions.
Based on these results we suggest that extended photometry and kinematics of
massive ETGs () can be used to estimate the local
fraction of ex-situ stars and to approximate the intrinsic shapes and
rotational support of the co-spatial dark matter component. [abridged]Comment: 22 pages, 17 figures, submitted to A&
Prolonged survival in the absence of disease-recurrence in advanced-stage follicular lymphoma following chemo-immunotherapy: 13-year update of the prospective, multicenter randomized GITMO-IIL trial
Aprospective trial conducted in the period 2000-2005 showed no survival advantage for high-dose chemotherapy with rituximab and autograft (RHDS) versus conventional chemotherapy with rituximab (CHOP-R) as firstline therapy in 134 high-risk follicular lymphoma patients aged <60 years. The study has been updated at the 13-year median follow up. As of February 2017, 88 (66%) patients were alive, with overall survival of 66.4% at 13 years, without a significant difference between R-HDS (64.5%) and CHOP-R (68.5%). To date, 46 patients have died, mainly because of disease progression (47.8% of all deaths), secondary malignancies (3 solid tumor, 9 myelodysplasia/acute leukemia; 26.1% of all deaths), and other toxicities (21.7% of all deaths). Complete remission was documented in 98 (73.1%) patients and associated with overall survival, with 13- year estimates of 77.0% and 36.8% for complete remission versus no-complete remission, respectively. Molecular remission was documented in 39 (65%) out of 60 evaluable patients and associated with improved survival. In multivariate analysis, complete remission achievement had the strongest effect on survival (P<0.001), along with younger age (P=0.002) and female sex (P=0.013). Overall, 50 patients (37.3%) survived with no disease recurrence (18 CHOP-R, 32 R-HDS). This follow up is the longest reported on follicular lymphoma treated upfront with rituximab-chemotherapy and demonstrates an unprecedented improvement in survival compared to the pre-rituximab era, regardless of the use of intensified or conventional treatment. Complete remission was the most important factor for prolonged survival and a high proportion of patients had prolonged survival in their first remission, raising the issue of curability in follicular lymphoma
Planetary nebulae populations in the haloes of nearby massive early-type galaxies
Planetary nebulae (PNe) are excellent tracers of the metal-poor haloes of
nearby early-type galaxies. They are commonly used to trace spatial
distribution and kinematics of the halo and intracluster light at distances of
up to 100 Mpcs. The results on the early-type galaxy M105 in the Leo I group
represent a benchmark for the quantitative analysis of halo and intragroup
light. Since the Leo I group lies at just a 10 Mpc distance, it is at the ideal
location to compare results from resolved stellar populations with the
homogeneous constraints over a much larger field of view from the PN
populations. In M105, we have -- for the first time -- established a direct
link between the presence of a metal-poor halo as traced by resolved red-giant
branch stars and a PN population with a high specific frequency
(-parameter). This confirms our inferences that the high
-parameter PN population in the outer halo of M49 in the Virgo Cluster
traces the metal-poor halo and intra-group light.Comment: 12 pages, 5 figures, accepted for publication in the proceedings of
IAU Symposium 384: Planetary Nebulae: a Universal Toolbox in the Era of
Precision Astrophysic
The classic prognostic factors in advanced Hodgkin\u2019s lymphoma patients are losing their meaning at the time of Pet-guided treatments
The International Prognostic Score (IPS) is the most commonly used risk stratification tool for patients with advanced Hodgkin lymphoma (HL). It incorporates seven clinical parameters independently associated with a poorer outcome: male sex, age, stage IV, hemoglobin level, white blood cell and lymphocyte counts, and albumin level. Since the development of the IPS, there have been significant advances in therapy and supportive care. Recent studies suggest that the IPS is less discriminating due to improved outcomes with ABVD therapy. The aim of the present study was to asses if classic prognostic factors maintain their prognostic meaning at the time of response-adapted treatment based on interim PET scans. We evaluated the prognostic significance of IPS in the 520 advanced stage HL patients enrolled in the PET-guided, HD0801 trial in which PET2-positive patients underwent a more intense treatment with an early stem-cell transplantation after 2 cycles of ABVD. We observed that in these patients, the IPS completely loses its prognostic value together with all the single parameters that contribute to the IPS. Furthermore, neutrophils, monocytes, lymphocytes, and the ratio among them also no longer had any predictive value. We believe that the substantial improvement in survival outcomes in PET2-positive patients treated with early autologous transplantation could explain the complete disappearance of the residual prognostic significance of the IPS
Acute myeloid leukemia in patients previously diagnosed with breast cancer: Experience of the GIMEMA group
Objective: To evaluate in a multicenter retrospective study, the clinical and laboratory characteristics and the outcome of patients with acute myeloid leukemia (sAML) previously diagnosed with breast cancer (BC) among an adult acute leukemia population. Patients and methods: Between June 1992 and July 1996, 3934 new cases of adults with acute leukemia were recorded in GIMEMA Archive of Adult Acute Leukemia (2964 AML, 901 ALL, 69 acute leukemia expressing both myeloid and lymphoid surface markers). Results: Two hundred patients (5.1%) presented with a history of previous malignancy (21 of them were affected by ALL and 179 by AML). Among sAML, 37 patients (29%) had a previous breast cancer. They consisted of 36 females and 1 male, median age 56 years, range 34-87. The median latency between the 2 malignancies was 54 months (range 5-379). Twenty-seven patients received chemo- and/or radiotherapy for breast cancer (7 only chemotherapy, 6 only radiotherapy, and 14 combined treatment). All patients were surgically treated but in 10 patients surgical debridement was the sole therapy for breast cancer. The drugs most frequently employed were alkylating agents (18 patients), topoisomerase II inhibitors (9 patients), antimetabolites (20 patients) (CMF, CEF and MMM combinations). At onset of sAML the median WBC count was 7.7 × 109/1 (0.8-153) and the median platelet count was 33.5 × 109/1 (3-305). Considering morphological features, FAB subtypes were 4 M0, 5 M1, 11 M2, 5 M3, 8 M4, 3 M5, and 1 M6. Cytogenetic study was performed on 28 patients and 12 of them presented abnormalities. It is noteworthy that chromosome 5 or 7 abnormalities (typically observed in those patients treated with alkylating agents) were present only in three cases. Thirty-four patients received chemotherapy for sAML, and twenty-five of them achieved a CR (74%), with a median duration of twenty-eight weeks (5-280+). The overall survival was 8 months (1-80+). Discussion: The high number of sAML we observed in patients with a previous breast cancer, may be due to the fact that this malignancy is the most frequent neoplasm in women and by the high probability of cure with a consequent long disease-free survival. Our results suggest that the risk of sAML after recovery from breast cancer is increasing due to the rise in the number of patients cured from breast cancer, and in the future could be a relevant problem for haematologists
INSPIRE: INvestigating Stellar Population In RElics II. First Data Release (DR1)
The INvestigating Stellar Population In RElics is an on-going project
targeting 52 ultra-compact massive galaxies at 0.1<z<0.5 with the X-Shooter@VLT
spectrograph (XSH). These objects are the perfect candidates to be 'relics',
massive red-nuggets formed at high-z (z>2) through a short and intense star
formation burst, that evolved passively and undisturbed until the present-day.
Relics provide a unique opportunity to study the mechanisms of star formation
at high-z. In this paper, we present the first INSPIRE Data Release, comprising
19 systems with observations completed in 2020. We use the methods already
presented in the INSPIRE Pilot, but revisiting the 1D spectral extraction. For
these 19 systems, we obtain an estimate of the stellar velocity dispersion,
fitting separately the two UVB and VIS XSH arms at their original resolution.
We estimate [Mg/Fe] abundances via line-index strength and mass-weighted
integrated stellar ages and metallicities with full spectral fitting on the
combined spectrum. Ages are generally old, in agreement with the photometric
ones, and metallicities are almost always super-solar, confirming the
mass-metallicity relation. The [Mg/Fe] ratio is also larger than solar for the
great majority of the galaxies, as expected. We find that 10 objects have
formed more than 75% of their stellar mass (M*) within 3 Gyr from the Big Bang
and classify them as relics. Among these, we identify 4 galaxies which had
already fully assembled their M* by that time. They are therefore `extreme
relics' of the ancient Universe. The INSPIRE DR1 catalogue of 10 known relics
to-date augment by a factor of 3.3 the total number of confirmed relics, also
enlarging the redshift window. It is therefore the largest publicly available
collection. Thanks to the larger number of systems, we can also better quantify
the existence of a 'degree of relicness', already hinted at the Pilot Paper.Comment: (Abstract abridged) 21 pages, 12 figures and 5 tables in the main
body, plus 3 figure and 1 table in the appendix, accepted for publication on
A&A. The associated data are available via the ESO Phase 3 Science Porta
Three dynamically distinct stellar populations in the halo of M49
Context: M49 (NGC 4472) is the dominant galaxy in subcluster B of the Virgo Cluster, and a benchmark for studying the build-up of the extended halos of brightest group galaxies in the outskirts of galaxy clusters.
Aims: We investigate the kinematics in the outer halo of M49, look for substructures, and describe the transition to the surrounding intra-group light.
Methods: As kinematic tracers we use planetary nebulae (PNe), combining kinematics from the extended Planetary Nebula Spectrograph (PN.S) early-type galaxy survey with our recent deep photometric sample. We study the position velocity-plane for bright and faint PN populations out to 95 kpc radius, and employ a multi-Gaussian model for the velocity distribution to identify stellar populations with distinct kinematics and histories.
Results: We report the detection of stellar-kinematic substructure associated with the interaction of M49 with the dwarf irregular galaxy VCC 1249. We find two kinematically distinct PN populations associated with the main M49 halo and the extended intragroup light (IGL). These have velocity dispersions sigma halo ~=170 km s-1 and sigma IGL ~= 400 km s-1 at 10-80 kpc radii. The overall luminosity profile and velocity dispersion at ~80 kpc are consistent with a flat circular velocity curve extrapolated from X-ray observations. The dispersion of the PNe associated with the IGL joins onto that of the satellite galaxies in subcluster B at ~ 100 kpc radius. This is the first time that the transition from halo to IGL is observed based on the velocities of individual stars.
Conclusions: Therefore the halo of M49, consisting of at least three distinct components, has undergone an extended accretion history within its parent group potential. The blue colours of the IGL component are consistent with a population of stars formed in low-mass galaxies at redshift ~0:5 that has since evolved passively, as suggested by other data
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