Probing the intracluster medium at high angular resolution via radio-interferometric measurements of the Sunyaev-Zeldovich effect

The work presented in this thesis is devoted to investigating the physics of galaxy clusters through the characterization of their Sunyaev-Zeldovich (SZ) effect signal observed by the Atacama Large Millimeter/Submillimeter Array (ALMA) and the Atacama Compact Array (ACA). The unparalleled capabilities of ALMA+ACA have definitely opened a millimeter-wave window on the physics of the intracluster medium. The pioneering observations of the SZ effect over scales of a few arcseconds demonstrated that ALMA+ACA can effectively provide a new observational tool, complementary to the more traditional X-ray observations, for probing the physical and thermodynamic state of the intracluster medium down to the smallest physical scales. Central for employing ALMA+ACA to map SZ structures are its outstanding sensitivity and angular resolving power. However, ALMA+ACA currently offers no sensitivity to any signal extending on scales larger than 1-2 arcminutes, as such information is severely filtered out through the interferometric response. A radio-interferometer can in fact provide measurements of signals with angular sizes solely corresponding to the inverse of the lengths of the individual baselines within the array. It follows that the pair of antennae at the smallest distance within an interferometer poses a hard limit on the maximum scale recoverable in a given observation. As galaxy clusters cover scales often larger than the field of view of ALMA, the result is a heavily high-pass filtered view of their SZ signature. In turn, both the proper interpretation of the reconstructed images and the analysis of the raw data become non trivial. To overcome the issue related to the large-scale filtering effect inherent to ALMA, it is key to combine the high-resolution ALMA+ACA measurements with complementary data or information. One possibility to tackle the lack of information on large scales is to consider SZ measurements from single-dish facilities. In fact, single-dish measurements generally have angular resolutions lower than radio-interferometric ones, but can recover sufficiently large angular scales to constrain the total SZ flux from a galaxy cluster. The reconstruction of the SZ signal from the joint analysis of radio-interferometric and single observations can thus be used to get insights into the physical state of small-scale structures within the intracluster medium as well as its global properties. The rich availability of SZ measurements of the renowned galaxy cluster RX J1347.5-1145 offered the opportunity to test such joint modelling approach. As the SZ effect provides information on the line-of-sight integral of the electron pressure distribution within a cluster, the joint study allowed to get a model of the intracluster pressure over an outstanding range of scales. Through the comparison with an independent analysis of X-ray measurements, this allowed for gaining novel insight into the thermodynamic properties of RX J1347.5-1145, as well as its formation history. The combination of SZ data with X-ray information is clearly central for obtaining a robust description of the intracluster gas and of any intracluster structures that attest to the dynamical nature of galaxy clusters. In particular, a joint SZ+X-ray high-resolution view of the shock fronts within galaxy clusters can help constraining a number of plasma properties fundamental to plasma physics on its own, as well as in the broader context of astrophysical processes, e.g., cluster and galaxy evolution, and the impact of merger and accretion processes of the cluster environment. Widely regarded as the "textbook example" of a cluster merger bow shock, the shock front in the "Bullet Cluster" (1E0657-56) represented the ideal test case for such an SZ study. The reconstruction of the shock properties specifically allowed for inferring the possible electron heating mechanisms taking place within the shocked gas. Finally, ALMA+ACA can serve as a powerful combination for providing direct and relatively inexpensive confirmation of galaxy clusters identified by other means (e.g., wide-field surveys at other wavelengths or with cosmic microwave background experiments) through the measure of their SZ signal. Although ALMA and ACA's mapping speeds are significantly lower than that of a SZ survey experiment, the angular resolution and sensitivity of ALMA+ACA allow one to easily measure the SZ effect from high-redshift systems. The study of a first pilot sample of galaxy cluster from the "Verification with the Atacama Compact Array - Localisation and Cluster Analysis" programme provided a first assessment of ACA's ability to get robust detections of high-redshift galaxy clusters and constraints on their masses.Die in dieser Dissertation präsentierte Arbeit widmet sich der Untersuchung der Physik von Galaxienhaufen mithilfe der Charakterisierung des Sunyaev-Zeldovich (SZ) Effekts in Beobachtung mit dem Atacama Large Millimeter/Submillimeter Array (ALMA) und dem Atacama Compact Array (ACA). Die beispiellosen Fähigkeiten von ALMA+ACA haben dem Studium der Physik des Mediums innerhalb von Galaxienhaufen ein Fenster im Millimeter WellenLängenbereich eröffnet. Die bahnbrechenden Beobachtungen des SZ Effekts auf Skalen von einigen Winkelsekunden haben gezeigt, dass ALMA+ACA effektiv ein neues Beobachtungswerkzeug bereitstellen können, welches komplementär zu den eher traditionellen Beobachtungen von Röntgenlicht ist, da dazu verwendet werden kann, den physikalischen und thermodynamischen Zustand des Mediums in Galaxienhaufen bis auf die kleinsten physikalischen Skalen zu testen. Von zentraler Bedeutung für den Einsatz von ALMA zur Abbildung von SZ Strukturen ist die herausragende Sensitivität und bisher unerreichte Winkelauflösung. Allerdings besitzt ALMA bisher noch keine Sensitivität für Signale, welche sich auf Skalen größer als 1-2 Winkelminuten erstrecken, da die Information über deren Präsenz durch die Verwendung von Interfermotrie stark heraus gefiltert wird. In der tat besitzen Messungen von Signalen durch Radio-interferometrie nur diejenigen Winkelskalen, welche den inversen Längen von individuellen Basislinien innerhalb des Arrays entsprechen. Daraus folgt, dass das Antennen Paar mit dem kleinsten Abstand innerhalb des Interferometers ein definitive obere Grenze für die maximal rekonstruierbare Größenskala in einer Beobachtung darstellt. Da sich die Größenskalen von Galaxienhaufen Längen erstrecken, welche über das Blickgeld von ALMA hinausgehen, verhalten sich SZ Signaturen als wären sie mit durch einen Hochpassfilter geschickt worden. Dementsprechend ist sowohl die richtige Interpretation der rekonstruierten Bilder als auch die Analyse von Rohdaten nicht trivial. Die Herausforderung, dass ALMA Beobachtungen grundlegend die größten Skalen heraus filtern, verlangt weitere komplementäre Daten/Informationen von hoch aufgelösten ALMA Messungen mit einander zu kombinieren. Eine Möglichkeit mit der fehlenden Information auf grossen Skalen umzugehen ist es, die SZ Messungen von einer einzelnen Teleskop-Einrichtung zu betrachten. Tatsächlich haben diese Messungen im allgemeinen kleinere Winkelauflösungen als deren radio-interferometrie Äquivalent, jedoch können sie hinreichend grosse Skalen rekonstruieren und sind damit in der Lage den gesamten SZ Stahlungsfluss eines Galaxienhaufens zu bestimmen. Die Rekonstruktion des SZ signals aus der gemeinsamen analyse von Radio-interferometrischen und einzelnen Beobachtungen kann deshalb dazu verwendet werden, sowohl Einsichten in den physikalischen Zustand der kleinskaligen Struktur innerhalb von des Galaxienhaufen-Mediums zu erhalten, als auch global dessen Eigenschaften zu bestimmen. Die grosse Verfügbarkeit von SZ Messungen des bekannten Galaxienhaufens RX J1347.5-1145 stellt die Möglichkeit für eine solche gleichzeitige Modellierung bereit. Gegeben, dass der SZ Effekt Information über die Elektronen-Druckverteilung innerhalb eines Galaxienhaufens entlang der Sichtlinie bereitstellt, erlaubte die Studie ein Modell der Druckverhältnisse innerhalb des Haufens auf bisher unerreichten Längenskalen zu erhalten. Durch den Vergleich mit Analysen von Messungen im RöntgenwellenLängenbereich, erlaubte dies sowohl neue Einsichten in die thermodynamischen Eigenschaften von RX J1347.5-1145 als auch dessen Entstehungsgeschichte. Die Kombination aus SZ Daten und Röntgenbeobachtungen ist erkenntlicherweise von zentraler Bedeutung fur eine robuste Beschreibung des Gases und der Strukturen innerhalb eines Galaxienhaufens, welche wiederum Rückschlüsse auf die dynamische Natur des Haufens zulassen. Insbesondere kann eine gemeinsame Betrachtung von hochaufgelösten SZ und Röntgenbeobachtungen eines Schocks innerhalb innerhalb von Galaxienhaufen dabei helfen, sowohl mehrere fundamentale Plasma Eigenschaften (und damit Plasmaphysik an sich), als auch im weiteren Kontext die Eigenschaften von astrophysikalischen Prozessen einzugrenzen, wie z.B. die Entwicklung von Galaxien und deren Haufen, oder den Einfluss von Akkretionsprozessen in der näheren Umgebung. Vielerseits gilt der bogenförmige Schock im sogenannten Bullet Cluster (1E0657-56) als das "Textbuch Beispiel" eines Idealfalls für eine SZ Studie. Die Rekonstruktion der Schock Eigenschaften erlaubte hier insbesondere die möglichen Erhitzungsmechanismen von Elektronen innerhalb des Schocks zu bestimmen. Letztendlich können ALMA+ACA als eine mächtige Kombination zur direkten und relativ günstigen Bestätigung bei der Identifikation von Galaxienhaufen dienen, welche über andere Mittel (wie z.B. Weitfeld Studien in anderen WellenLängen or CMB experimenten) beobachtet wurden, insbesondere durch die Messung derer SZ Signale. Obwohl ALMAs Abbildungsgeschwindigkeit signifikant kleiner ist als die von Experimenten zur Erhebung von SZ Strukturen, erlauben einem die Winkelauflösung und Sensitivität von ALMA doch eine einfache Messung des SZ Effekts in Systemen mit hoher Rotverschiebung. Die erst Pilotstudie einer Galaxienhaufen Stichprobe des VACA LoCA (engl. für "Verification with the Atacama Compact Array - Localisation and Cluster Analysis") erlaubte bereits eine erste Beurteilung von ACA Fähigkeiten eine robuste Detektion von Galaxienhaufen mit hoher Rotverschiebung samt Massenbestimmungen durchzuführen

Probing the intracluster medium at high angular resolution via radio-interferometric measurements of the Sunyaev-Zeldovich effect

The work presented in this thesis is devoted to investigating the physics of galaxy clusters through the characterization of their Sunyaev-Zeldovich (SZ) effect signal observed by the Atacama Large Millimeter/Submillimeter Array (ALMA) and the Atacama Compact Array (ACA). The unparalleled capabilities of ALMA+ACA have definitely opened a millimeter-wave window on the physics of the intracluster medium. The pioneering observations of the SZ effect over scales of a few arcseconds demonstrated that ALMA+ACA can effectively provide a new observational tool, complementary to the more traditional X-ray observations, for probing the physical and thermodynamic state of the intracluster medium down to the smallest physical scales. Central for employing ALMA+ACA to map SZ structures are its outstanding sensitivity and angular resolving power. However, ALMA+ACA currently offers no sensitivity to any signal extending on scales larger than 1-2 arcminutes, as such information is severely filtered out through the interferometric response. A radio-interferometer can in fact provide measurements of signals with angular sizes solely corresponding to the inverse of the lengths of the individual baselines within the array. It follows that the pair of antennae at the smallest distance within an interferometer poses a hard limit on the maximum scale recoverable in a given observation. As galaxy clusters cover scales often larger than the field of view of ALMA, the result is a heavily high-pass filtered view of their SZ signature. In turn, both the proper interpretation of the reconstructed images and the analysis of the raw data become non trivial. To overcome the issue related to the large-scale filtering effect inherent to ALMA, it is key to combine the high-resolution ALMA+ACA measurements with complementary data or information. One possibility to tackle the lack of information on large scales is to consider SZ measurements from single-dish facilities. In fact, single-dish measurements generally have angular resolutions lower than radio-interferometric ones, but can recover sufficiently large angular scales to constrain the total SZ flux from a galaxy cluster. The reconstruction of the SZ signal from the joint analysis of radio-interferometric and single observations can thus be used to get insights into the physical state of small-scale structures within the intracluster medium as well as its global properties. The rich availability of SZ measurements of the renowned galaxy cluster RX J1347.5-1145 offered the opportunity to test such joint modelling approach. As the SZ effect provides information on the line-of-sight integral of the electron pressure distribution within a cluster, the joint study allowed to get a model of the intracluster pressure over an outstanding range of scales. Through the comparison with an independent analysis of X-ray measurements, this allowed for gaining novel insight into the thermodynamic properties of RX J1347.5-1145, as well as its formation history. The combination of SZ data with X-ray information is clearly central for obtaining a robust description of the intracluster gas and of any intracluster structures that attest to the dynamical nature of galaxy clusters. In particular, a joint SZ+X-ray high-resolution view of the shock fronts within galaxy clusters can help constraining a number of plasma properties fundamental to plasma physics on its own, as well as in the broader context of astrophysical processes, e.g., cluster and galaxy evolution, and the impact of merger and accretion processes of the cluster environment. Widely regarded as the "textbook example" of a cluster merger bow shock, the shock front in the "Bullet Cluster" (1E0657-56) represented the ideal test case for such an SZ study. The reconstruction of the shock properties specifically allowed for inferring the possible electron heating mechanisms taking place within the shocked gas. Finally, ALMA+ACA can serve as a powerful combination for providing direct and relatively inexpensive confirmation of galaxy clusters identified by other means (e.g., wide-field surveys at other wavelengths or with cosmic microwave background experiments) through the measure of their SZ signal. Although ALMA and ACA's mapping speeds are significantly lower than that of a SZ survey experiment, the angular resolution and sensitivity of ALMA+ACA allow one to easily measure the SZ effect from high-redshift systems. The study of a first pilot sample of galaxy cluster from the "Verification with the Atacama Compact Array - Localisation and Cluster Analysis" programme provided a first assessment of ACA's ability to get robust detections of high-redshift galaxy clusters and constraints on their masses.Die in dieser Dissertation präsentierte Arbeit widmet sich der Untersuchung der Physik von Galaxienhaufen mithilfe der Charakterisierung des Sunyaev-Zeldovich (SZ) Effekts in Beobachtung mit dem Atacama Large Millimeter/Submillimeter Array (ALMA) und dem Atacama Compact Array (ACA). Die beispiellosen Fähigkeiten von ALMA+ACA haben dem Studium der Physik des Mediums innerhalb von Galaxienhaufen ein Fenster im Millimeter WellenLängenbereich eröffnet. Die bahnbrechenden Beobachtungen des SZ Effekts auf Skalen von einigen Winkelsekunden haben gezeigt, dass ALMA+ACA effektiv ein neues Beobachtungswerkzeug bereitstellen können, welches komplementär zu den eher traditionellen Beobachtungen von Röntgenlicht ist, da dazu verwendet werden kann, den physikalischen und thermodynamischen Zustand des Mediums in Galaxienhaufen bis auf die kleinsten physikalischen Skalen zu testen. Von zentraler Bedeutung für den Einsatz von ALMA zur Abbildung von SZ Strukturen ist die herausragende Sensitivität und bisher unerreichte Winkelauflösung. Allerdings besitzt ALMA bisher noch keine Sensitivität für Signale, welche sich auf Skalen größer als 1-2 Winkelminuten erstrecken, da die Information über deren Präsenz durch die Verwendung von Interfermotrie stark heraus gefiltert wird. In der tat besitzen Messungen von Signalen durch Radio-interferometrie nur diejenigen Winkelskalen, welche den inversen Längen von individuellen Basislinien innerhalb des Arrays entsprechen. Daraus folgt, dass das Antennen Paar mit dem kleinsten Abstand innerhalb des Interferometers ein definitive obere Grenze für die maximal rekonstruierbare Größenskala in einer Beobachtung darstellt. Da sich die Größenskalen von Galaxienhaufen Längen erstrecken, welche über das Blickgeld von ALMA hinausgehen, verhalten sich SZ Signaturen als wären sie mit durch einen Hochpassfilter geschickt worden. Dementsprechend ist sowohl die richtige Interpretation der rekonstruierten Bilder als auch die Analyse von Rohdaten nicht trivial. Die Herausforderung, dass ALMA Beobachtungen grundlegend die größten Skalen heraus filtern, verlangt weitere komplementäre Daten/Informationen von hoch aufgelösten ALMA Messungen mit einander zu kombinieren. Eine Möglichkeit mit der fehlenden Information auf grossen Skalen umzugehen ist es, die SZ Messungen von einer einzelnen Teleskop-Einrichtung zu betrachten. Tatsächlich haben diese Messungen im allgemeinen kleinere Winkelauflösungen als deren radio-interferometrie Äquivalent, jedoch können sie hinreichend grosse Skalen rekonstruieren und sind damit in der Lage den gesamten SZ Stahlungsfluss eines Galaxienhaufens zu bestimmen. Die Rekonstruktion des SZ signals aus der gemeinsamen analyse von Radio-interferometrischen und einzelnen Beobachtungen kann deshalb dazu verwendet werden, sowohl Einsichten in den physikalischen Zustand der kleinskaligen Struktur innerhalb von des Galaxienhaufen-Mediums zu erhalten, als auch global dessen Eigenschaften zu bestimmen. Die grosse Verfügbarkeit von SZ Messungen des bekannten Galaxienhaufens RX J1347.5-1145 stellt die Möglichkeit für eine solche gleichzeitige Modellierung bereit. Gegeben, dass der SZ Effekt Information über die Elektronen-Druckverteilung innerhalb eines Galaxienhaufens entlang der Sichtlinie bereitstellt, erlaubte die Studie ein Modell der Druckverhältnisse innerhalb des Haufens auf bisher unerreichten Längenskalen zu erhalten. Durch den Vergleich mit Analysen von Messungen im RöntgenwellenLängenbereich, erlaubte dies sowohl neue Einsichten in die thermodynamischen Eigenschaften von RX J1347.5-1145 als auch dessen Entstehungsgeschichte. Die Kombination aus SZ Daten und Röntgenbeobachtungen ist erkenntlicherweise von zentraler Bedeutung fur eine robuste Beschreibung des Gases und der Strukturen innerhalb eines Galaxienhaufens, welche wiederum Rückschlüsse auf die dynamische Natur des Haufens zulassen. Insbesondere kann eine gemeinsame Betrachtung von hochaufgelösten SZ und Röntgenbeobachtungen eines Schocks innerhalb innerhalb von Galaxienhaufen dabei helfen, sowohl mehrere fundamentale Plasma Eigenschaften (und damit Plasmaphysik an sich), als auch im weiteren Kontext die Eigenschaften von astrophysikalischen Prozessen einzugrenzen, wie z.B. die Entwicklung von Galaxien und deren Haufen, oder den Einfluss von Akkretionsprozessen in der näheren Umgebung. Vielerseits gilt der bogenförmige Schock im sogenannten Bullet Cluster (1E0657-56) als das "Textbuch Beispiel" eines Idealfalls für eine SZ Studie. Die Rekonstruktion der Schock Eigenschaften erlaubte hier insbesondere die möglichen Erhitzungsmechanismen von Elektronen innerhalb des Schocks zu bestimmen. Letztendlich können ALMA+ACA als eine mächtige Kombination zur direkten und relativ günstigen Bestätigung bei der Identifikation von Galaxienhaufen dienen, welche über andere Mittel (wie z.B. Weitfeld Studien in anderen WellenLängen or CMB experimenten) beobachtet wurden, insbesondere durch die Messung derer SZ Signale. Obwohl ALMAs Abbildungsgeschwindigkeit signifikant kleiner ist als die von Experimenten zur Erhebung von SZ Strukturen, erlauben einem die Winkelauflösung und Sensitivität von ALMA doch eine einfache Messung des SZ Effekts in Systemen mit hoher Rotverschiebung. Die erst Pilotstudie einer Galaxienhaufen Stichprobe des VACA LoCA (engl. für "Verification with the Atacama Compact Array - Localisation and Cluster Analysis") erlaubte bereits eine erste Beurteilung von ACA Fähigkeiten eine robuste Detektion von Galaxienhaufen mit hoher Rotverschiebung samt Massenbestimmungen durchzuführen

A joint ALMA-Bolocam-Planck SZ study of the pressure distribution in RX J1347.5-1145

We report the joint analysis of single-dish and interferometric observations of the Sunyaev-Zeldovich (SZ) effect from the galaxy cluster RX J1347.5-1145. We have developed a parametric fitting procedure that uses native imaging and visibility data, and tested it using the rich data sets from ALMA, Bolocam, and Planck available for this object. RX J1347.5-1145 is a very hot and luminous cluster showing signatures of a merger. Previous X-ray-motivated SZ studies have highlighted the presence of an excess SZ signal south-east of the X-ray peak, which was generally interpreted as a strong, shock-induced pressure perturbation. Our model, when centred at the X-ray peak, confirms this. However, the presence of two almost equally bright giant elliptical galaxies separated by $\sim100\;{\rm kpc}$ makes the choice of the cluster centre ambiguous, and allows for considerable freedom in modelling the structure of the galaxy cluster. For instance, we have shown that the SZ signal can be well-described by a single smooth ellipsoidal generalized Navarro-Frenk-White profile, where the best-fitting centroid is located between the two brightest cluster galaxies. This leads to a considerably weaker excess SZ signal from the south-eastern substructure. Further, the most prominent features seen in the X-ray can be explained as predominantly isobaric structures, alleviating the need for highly supersonic velocities, although overpressurized regions associated with the moving subhaloes are still present in our model.Comment: 20 pages (including appendices), 11 figures, and 4 tables; accepted for publication in MNRA

Edukoi: developing an interactive sonification tool for astronomy between entertainment and education

Edukoi is a software that aims to make interactive sonification suitable to convey and extract information. The program design is a modification of the software Herakoi, which sonifies images in real time mapping pitch to colour using a motion-aware approach for allowing users to interact with images through sound. The pitch-colour association of Hearkoi, albeit pleasing from the entertainment side, is not efficient for communicating specific information regarding colours and hues to listeners. Hence we modified it to create an instrument to be used by visually impaired and sighted children to explore images through sound and extract accurate information. We aim at building a flexible software that can be used in middle-schools for both art and science teaching. We tested its effectiveness using astronomical images, given the great fascination that astronomy always has on kids of all ages and backgrounds. Astronomy is also considered a very visual science, a characteristic that prevents students from learning this subject and having a related career. With this project we aim to challenge this belief and give to students the possibility to explore astronomical data through sound. Here we discuss our experiment, the choices we made regarding sound mappings, and what psychophysiological aspects we aim to evaluate to validate and improve Edukoi.Comment: 4 pages, 3 figures, to be published in the proceedings of "The 28th International Conference on Auditory Display (ICAD 2023) - Special Session on Astronomical Data Sonification

The Massive and Distant Clusters of WISE Survey: SZ effect Verification with the Atacama Compact Array -- Localization and Cluster Analysis

The Massive and Distant Clusters of WISE Survey (MaDCoWS) provides a catalog of high-redshift ($0.7\lesssim z\lesssim 1.5$) infrared-selected galaxy clusters. However, the verification of the ionized intracluster medium, indicative of a collapsed and nearly virialized system, is made challenging by the high redshifts of the sample members. The main goal of this work is to test the capabilities of the Atacama Compact Array (ACA; also known as the Morita Array) Band 3 observations, centered at about 97.5 GHz, to provide robust validation of cluster detections via the thermal Sunyaev-Zeldovich (SZ) effect. Using a pilot sample that comprises ten MaDCoWS galaxy clusters, accessible to ACA and representative of the median sample richness, we infer the masses of the selected galaxy clusters and respective detection significance by means of a Bayesian analysis of the interferometric data. Our test of the "Verification with the ACA - Localization and Cluster Analysis" (VACA LoCA) program demonstrates that the ACA can robustly confirm the presence of the virialized intracluster medium in galaxy clusters previously identified in full-sky surveys. In particular, we obtain a significant detection of the SZ effect for seven out of the ten VACA LoCA clusters. We note that this result is independent of the assumed pressure profile. However, the limited angular dynamic range of the ACA in Band 3 alone, short observational integration times, and possible contamination from unresolved sources limit the detailed characterization of the cluster properties and the inference of the cluster masses within scales appropriate for the robust calibration of mass-richness scaling relations.Comment: 19 pages (including appendices), 14 figures, and 4 tables; accepted for publication in A&

To See or Not to See a z∼13z\sim13 Galaxy? That is the Question

``When did the first galaxies form?'' is still one of the greatest unanswered questions in astronomy. Theory and current stellar population models imply that the first galaxies formed at least at z=14-15. Yet, the highest redshift galaxy to have been securely confirmed remains GN-z11, at z$\sim$11. The galaxy ``HD1'' was recently proposed to be a z=13.27 galaxy based on its potential Lyman break and tentative [O III] 88 {\mu}m detection with ALMA. We hereby aim to test this scenario with new ALMA Band 4, DDT observations of what would be the [C II] 158 {\mu}m emission, if HD1 is at z$\sim$13.27. We carefully analyse the new ALMA Band 4 observations as well as re-analysing the existing ALMA Band 6 data on the source to determine the proposed redshift. We find a tentative $4\sigma$ feature in the Band 4 data that is spatially offset by 1.7" and spectrally offset by 190 km s-1 from the previously-reported $3.8\sigma$ ``[O III] 88 {\mu}m'' feature. Through various statistical tests, we demonstrate that these tentative features are fully consistent with being random noise features. The chances of finding a noise peak of the same significance as the tentative [C II] and [O III] features are 50\% and 100\%, respectively. Given the noise properties of the ALMA data, we recover at least a 50\% chance of finding two, matched $\geq3.8\sigma$ noise peaks that are spatially and spectrally offset by $\leq$10 kpc and 1000 km s-1. We conclude that we are more likely to be recovering noise features than both [O III] and [C II] emission from a source at $z\sim 13.27$. Although we find no evidence of a $z\sim 13.27$ galaxy, we cannot entirely rule out this scenario. Non-detections are also possible for a $z\sim 13$ source with a low interstellar gas-phase metallicity and density. Determining where and exactly what type of galaxy HD1 is, will now likely require JWST/NIRSpec spectroscopy.Comment: Submitted to A&A, 9 pages, 6 figures

Vascular-confined multi-passage discoidal nanoconstructs for the low-dose docetaxel inhibition of triple-negative breast cancer growth

AbstractTaxane efficacy in triple negative breast cancer (TNBC) is limited by insufficient tumor accumulation and severe off-target effects. Nanomedicines offer a unique opportunity to enhance the anti-cancer potency of this drug. Here, 1,000 nm × 400 nm discoidal polymeric nanoconstructs (DPN) encapsulating docetaxel (DTXL) and the near infrared compound lipid-Cy5 were engineered. DPN were obtained by filling multiple times cylindrical wells in a poly(vinyl alcohol) template with a polymer mixture comprising poly(lactic-co-glycolic acid) (PLGA) and poly(ethylene glycol) diacrylate (PEG-DA) chains together with therapeutic and imaging agents. The resulting "multi-passage" DPN exhibited higher DTXL loading, lipid-Cy5 stability, and stiffness as compared to the conventional "single-passage" approach. Confocal microscopy confirmed that DTXL-DPN were not taken up by MDA-MB-231 cells but would rather sit next to the cell membrane and slowly release DTXL thereof. Empty DPN had no toxicity on TNBC cells, whereas DTXL-DPN presented a cytotoxic potential comparable to free DTXL (IC50 = 2.6 nM ± 1.0 nM vs. 7.0 nM ± 1.09 nM at 72 h). In orthotopic murine models, DPN accumulated in TNBC more efficiently than free-DTXL. With only 2 mg/kg DTXL, intravenously administered every 2 days for a total of 13 treatments, DTXL-DPN induced tumor regression and were associated to an overall 80% survival rate as opposed to a 30% survival rate for free-DTXL, at 120 days. All untreated mice succumbed before 90 days. Collectively, this data demonstrates that vascular confined multi-passage DPN, biomimicking the behavior of circulating platelets, can efficiently deliver chemotherapeutic molecules to malignant tissues and effectively treat orthotopic TNBC at minimal taxane doses

Prognostic factors in Krukenberg tumor

BACKGROUND: Krukenberg tumor (KT) is a rare secondary ovarian tumor. Little is known about clinicopathologic factors affecting prognosis in KT. OBJECTIVE: To assess the prognostic value of clinicopathologic factors in KT through a systematic review and meta-analysis. METHODS: Electronic databases were searched from their inception to February 2019 for studies assessing the association of clinicopathologic factors with overall survival in KT. Pooled hazard ratio (HR) was calculated for each factor; a p value < 0.05 was considered significant. RESULTS: Twenty-three studies with 1743 patients were included. A decreased overall survival was significantly associated with peritoneal involvement (HR 1.944; p = 0.003), ascites (HR 2.055; p = 0.034), synchronous presentation (HR 1.679; p = 0.034) and increased serum CEA levels (HR 1.380; p = 0.010), but not with age > 50 (HR 0.946; p = 0.743), menopausal status (HR 1.565; p = 0.204), gastric origin (HR 1.600; p = 0.201), size > 5 cm (HR 1.292; p = 0.119), size > 10 cm (HR 0.925; p = 0.714), bilateral ovarian involvement (HR 1.113; p = 0.347), non-peritoneal extaovarian metastases (HR 1.648; p = 0.237), liver metastases (HR 1.118, p = 0.555), predominant signet ring cell morphology (HR 1.322; p = 0.208) and levels of CA125 (HR 0.933; p = 0.828) and CA19.9 (HR 0.996; p = 0.992). CONCLUSION: Peritoneal involvement, synchronous presentation, ascites and increased serum CEA levels appear as unfavorable prognostic factors in KT and might affect the patient management

High resolution modeling of [CII], [CI], [OIII] and CO line emission from the ISM and CGM of a star forming galaxy at z ~ 6.5

The circumgalactic medium (CGM) is a crucial component of galaxy evolution, but thus far its physical properties are highly unconstrained. As of yet, no cosmological simulation has reached convergence when it comes to constraining the cold and dense gas fraction of the CGM. Such components are also challenging to observe, and require sub-millimeter instruments with a high sensitivity to extended, diffuse emission, like the proposed Atacama Large Aperture Sub-millimetre telescope (AtLAST). We present a state-of-the-art theoretical effort at modeling the [CII], [CI](1-0), [CI](2-1), CO(3-2), and [OIII] line emissions of galaxies. We use the high-resolution cosmological zoom-in simulation Ponos, representing a star forming galaxy system at z = 6.5 ($M_*=2\times10^9~M_{\odot}$), undergoing a major merger. We adopt different modeling approaches based on the photoionisation code Cloudy. Our fiducial model uses radiative transfer post-processing with RamsesRT and Krome to create realistic FUV radiation fields, which we compare to sub-grid modeling approaches adopted in the literature. We find significant differences in the luminosity and in the contribution of different gas phases and galaxy components between the different modeling approaches. [CII] is the least model-dependant gas tracer, while [CI](1-0) and CO(3-2) are very model-sensitive. In all models, we find a significant contribution to the emission of [CII] (up to $\sim$10%) and [OIII] (up to $\sim$20%) from the CGM. [CII] and [OIII] trace different regions of the CGM: [CII] arises from an accreting filament and from tidal tails, while [OIII] traces a puffy halo surrounding the main disc, probably linked to SN feedback. We discuss our results in the context of current and future sub-mm observations with ALMA and AtLAST.Comment: Submitted for publication to A&A. 25 pages, 17 figures. Abstract summarised for arXiv submissio

Forming intracluster gas in a galaxy protocluster at a redshift of 2.16

Galaxy clusters are the most massive gravitationally bound structures in the Universe, comprising thousands of galaxies and pervaded by a diffuse, hot intracluster medium (ICM) that dominates the baryonic content of these systems. The formation and evolution of the ICM across cosmic time1 is thought to be driven by the continuous accretion of matter from the large-scale filamentary surroundings and energetic merger events with other clusters or groups. Until now, however, direct observations of the intracluster gas have been limited only to mature clusters in the later three-quarters of the history of the Universe, and we have been lacking a direct view of the hot, thermalized cluster atmosphere at the epoch when the first massive clusters formed. Here we report the detection (about 6σ) of the thermal Sunyaev-Zeldovich (SZ) effect2 in the direction of a protocluster. In fact, the SZ signal reveals the ICM thermal energy in a way that is insensitive to cosmological dimming, making it ideal for tracing the thermal history of cosmic structures3. This result indicates the presence of a nascent ICM within the Spiderweb protocluster at redshift z = 2.156, around 10 billion years ago. The amplitude and morphology of the detected signal show that the SZ effect from the protocluster is lower than expected from dynamical considerations and comparable with that of lower-redshift group-scale systems, consistent with expectations for a dynamically active progenitor of a local galaxy cluster