The ALMA REBELS survey: obscured star formation in massive Lyman-break galaxies at z = 4-8 revealed by the IRX-β\beta and M⋆M_{\star} relations

We investigate the degree of dust obscured star formation in 49 massive (${\rm log}_{10}(M_{\star}/{\rm M}_{\odot})>9$) Lyman-break galaxies (LBGs) at $z = 6.5$-$8$ observed as part of the ALMA Reionization Era Bright Emission Line Survey (REBELS) large program. By creating deep stacks of the photometric data and the REBELS ALMA measurements we determine the average rest-frame UV, optical and far-infrared (FIR) properties which reveal a significant fraction ($f_{\rm obs} = 0.4$-$0.7$) of obscured star formation, consistent with previous studies. From measurements of the rest-frame UV slope, we find that the brightest LBGs at these redshifts show bluer ($\beta \simeq -2.2$) colours than expected from an extrapolation of the colour-magnitude relation found at fainter magnitudes. Assuming a modified blackbody spectral-energy distribution (SED) in the FIR (with dust temperature of $T_{\rm d} = 46\,{\rm K}$ and $\beta_{\rm d} = 2.0$), we find that the REBELS sources are in agreement with the local ''Calzetti-like'' starburst Infrared-excess (IRX)-$\beta$ relation. By reanalysing the data available for 108 galaxies at $z \simeq 4$-$6$ from the ALPINE ALMA large program using a consistent methodology and assumed FIR SED, we show that from $z \simeq 4$-$8$, massive galaxies selected in the rest-frame UV have no appreciable evolution in their derived IRX-$\beta$ relation. When comparing the IRX-$M_{\star}$ relation derived from the combined ALPINE and REBELS sample to relations established at $z < 4$, we find a deficit in the IRX, indicating that at $z > 4$ the proportion of obscured star formation is lower by a factor of $\gtrsim 3$ at a given a $M_{\star}$. Our IRX-$\beta$ results are in good agreement with the high-redshift predictions of simulations and semi-analytic models for $z \simeq 7$ galaxies with similar stellar masses and SFRs.Comment: 18 pages, 10 figures, 2 tables (plus 1 figure and 2 tables in the appendix). Updated to match MNRAS accepted version after minor correction

The ALMA REBELS survey: obscured star formation in massive Lyman-break galaxies at z = 4-8 revealed by the IRX-β and M*relations

We investigate the degree of dust obscured star formation in 49 massive (log 10 ( M*/M ⊙) > 9) Lyman-break galaxies (LBGs) at z = 6.5-8 observed as part of the Atacama Large Millimeter/submillimeter Array (ALMA) Reionization Era Bright Emission Line Surv e y (REBELS) large program. By creating deep stacks of the photometric data and the REBELS ALMA measurements we determine the average rest-frame ultraviolet (UV), optical, and far-infrared (FIR) properties which reveal a significant fraction ( f obs = 0.4-0.7) of obscured star formation, consistent with previous studies. From measurements of the rest-frame UV slope, we find that the brightest LBGs at these redshifts show bluer ( β≃ -2.2) colours than expected from an extrapolation of the colour-magnitude relation found at fainter magnitudes. Assuming a modified blackbody spectral energy distribution (SED) in the FIR (with dust temperature of T d = 46 K and βd = 2.0), we find that the REBELS sources are in agreement with the local 'Calzetti-like' starburst Infrared-excess (IRX)-βrelation. By re-analysing the data available for 108 galaxies at z ≃ 4-6 from the ALMA Large Program to Investigate C + at Early Times (ALPINE) using a consistent methodology and assumed FIR SED, we show that from z ≃ 4-8, massive galaxies selected in the rest-frame UV have no appreciable evolution in their derived IRX-βrelation. When comparing the IRX-M*relation derived from the combined ALPINE and REBELS sample to relations established at z 4 the proportion of obscured star formation is lower by a factor of ≳3 at a given a M*. Our IRX-βresults are in good agreement with the high-redshift predictions of simulations and semi-analytic models for z ≃ 7 galaxies with similar stellar masses and star formation rates

Carcinoma hemorrhagiectoides: case report of an uncommon presentation of cutaneous metastatic breast carcinoma.

In most cases, cutaneous metastases develop after the diagnosis of the primary internal malignancy has been established, but sometimes they can be discovered earlier or simultaneously. We describe a case of a 90-year-old woman who presented to the emergency room in poor general condition, with cutaneous lesions characterized by hot, infiltrated, violaceous and erythematous plaques involving the left chest wall. The clinical and histopathological findings were consistent with the recently described variant of inflammatory cutaneous metastatic carcinoma named carcinoma hemorrhagiectoides. Microscopic examination demonstrated extensive infiltration of the dermis by tumor cells as well as intralymphatic involvement by neoplastic cells. This is a very rare presentation of cutaneous metastasis from breast cancer

Pigmented basal cell carcinoma mimicking a superficial spreading melanoma

Resumen El carcinoma basocelular es el cáncer de piel más frecuente, especialmente en personas de edad avanzada. El carcinoma basocelular pigmentado es una variante poco común que se ha descrito en la literatura como una lesión nodular hiperpigmentada. En raras ocasiones puede presentarse en forma de una extensa placa pigmentada, la cual puede ser clínicamente indistinguible del melanoma maligno de extensión superficial y de la enfermedad de Bowen. La dermatoscopía tiene una alta sensibilidad en el diagnóstico del carcinoma basocelular, cuando se utilizan los criterios de Menzies, aunque el diagnóstico final es histopatológico. El objetivo del presente trabajo es reportar y analizar el caso de una paciente con un extenso carcinoma basocelular superficial pigmentado, que simula un melanoma maligno de extensión superficial

Enfermedad de Kyrle: reporte de un caso con buena respuesta a terapia tópica

Introducción: La enfermedad de Kyrle (EK) corresponde a una dermatosis perforante adquirida (DPA), grupo raro de enfermedades que se caracterizan por la eliminación transepidérmica de material dérmico, asociado a la presencia de enfermedades sistémicas. Caso Clínico: Paciente masculino de 57 años con antecedente de enfermedad renal crónica (ERC) en peritoneodiálisis de larga data, que presenta pápulas queratósicas de bordes violáceos en dorso, pruriginosas de 9 meses de evolución, con pigmentación marrón periférica y tapones blanquecinos asociadas a xerosis y signos de grataje, en cuya biopsia se detectan hallazgos compatibles con EK. Discusión: El caso presentado corresponde a una manifestación típica de la EK en un paciente con factores de riesgo, en el cual la dermatoscopía es compatible y la biopsia es esencial para la confirmación del cuadro dada la similitud clínica con otros diagnósticos diferenciales. Además de la dificultad para establecer el diagnóstico, existe escasa evidencia que demuestre la efectividad de las diferentes terapias planteadas para este cuadro, siendo de difícil manejo y de gran recurrencia. El manejo tópico con corticoides tópicos y humectantes, opción terapéutica elegida, mostró una respuesta favorable a largo plazo, exponiendo la potencialidad de convertirse en el manejo inicial de elección ante la presencia de lesiones localizadas