Video Experimental Relacionado
Updated: Jul 12, 2026
10:01
Demonstration of a Hyperlens-integrated Microscope and Super-resolution Imaging
Published on: September 8, 2017
Magnificación de la luz de muchos cuásares distantes por lentes gravitacionales
J Stuart B Wyithe1, Abraham Loeb
1Astronomy Department, Harvard University, 60 Garden Street, Cambridge, Massachusetts 02138, USA.
Nature
|June 28, 2002
Resumen
La lente gravitacional puede magnificar significativamente el flujo observado de cuásares distantes. Este fenómeno cósmico significa que la abundancia y la luminosidad de los primeros cuásares pueden haber sido sobreestimados por los astrónomos.
Área de la Ciencia:
- Cosmología Cosmología.
- La astrofísica es la astrofísica.
- Evolución de la galaxia Evolución de la galaxia.
Sus antecedentes:
- Se han descubierto quásares brillantes con altos desplazamientos al rojo (z hasta 6.28), lo que desafía los modelos de formación del Universo temprano.
- Estos quásares son alimentados por agujeros negros supermasivos (SMBH) con masas que exceden miles de millones de masas solares.
- La rápida formación de tales agujeros negros masivos dentro de los primeros mil millones de años después del Big Bang es un rompecabezas cosmológico significativo.
Objetivo del estudio:
- Para investigar el impacto de la lente gravitacional en las propiedades observadas de los cuásares de alto desplazamiento al rojo.
- Para reevaluar la abundancia inferida y la densidad de luminosidad de los cuásares en z aproximadamente igual a 6.
- Para evaluar el papel de las galaxias intermedias en la ampliación del flujo de cuásares.
Principales métodos:
- Análisis de los datos de observación de los cuásares en z aproximadamente igual a 6.
- Modelado de los efectos de lente gravitacional por las galaxias de primer plano a lo largo de la línea de visión.
- Cuantificación del factor de aumento del flujo de cuásar debido a la lente.
Principales resultados:
- Hasta un tercio de los cuásares observados en z aproximadamente igual a 6 pueden experimentar una ampliación de flujo de diez veces o más.
- La lente gravitacional de las galaxias que intervienen es un factor significativo que afecta las observaciones de cuásares.
- La abundancia inferida de galaxias anfitrionas de cuásares ha sido sustancialmente sobreestimada.
Conclusiones:
- El brillo observado de los quásares de alto desplazamiento al rojo puede ser amplificado significativamente por la lente gravitacional.
- Las estimaciones anteriores de la densidad de luminosidad de los cuásares y la abundancia de galaxias anfitrionas en los primeros tiempos cósmicos requieren revisión.
- La lente gravitacional debe tenerse en cuenta al estudiar cuásares distantes y poblaciones de galaxias primitivas.
Videos de Conceptos Relacionados
01:21Schwarzschild Radius and Event Horizon
No object with a finite mass can travel faster than the speed of light in a vacuum. This fact has an interesting consequence in the domain of extremely high gravitational fields.
The minimum speed required to launch a projectile from the surface of an object to which it is gravitationally bound so that it eventually escapes the object’s gravitational field is called the escape velocity. The escape velocity is independent of the mass of the object. Merging the idea of escape velocity with the...
The minimum speed required to launch a projectile from the surface of an object to which it is gravitationally bound so that it eventually escapes the object’s gravitational field is called the escape velocity. The escape velocity is independent of the mass of the object. Merging the idea of escape velocity with the...
01:10Detection of Black Holes
Although black holes were theoretically postulated in the 1920s, they remained outside the domain of observational astronomy until the 1970s.
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
Their closest cousins are neutron stars, which are composed almost entirely of neutrons packed against each other, making them extremely dense. A neutron star has the same mass as the Sun but its diameter is only a few kilometers. Therefore, the escape velocity from their surface is close to the speed of light.
Not until the 1960s, when the first neutron...
01:18Imaging Biological Samples with Optical Microscopy
Optical microscopy uses optic principles to provide detailed images of samples. Antonie van Leeuwenhoek designed the first compound optical microscope in the 17th century to visualize blood cells, bacteria, and yeast cells. In 1830, Joseph Jackson Lister created an essentially modern light microscope. The 20th century saw the development of microscopes with enhanced magnification and resolution.
In optical microscopy, the specimen to be viewed is placed on a glass slide and clipped on the stage...
In optical microscopy, the specimen to be viewed is placed on a glass slide and clipped on the stage...
01:16Confocal Fluorescence Microscopy
Confocal microscopy is an advanced microscopic technique. The prime advantage of the confocal microscope over other microscopy techniques is its ability to block the out-of-focus light from the illuminated samples using pinholes. It is widely used with fluorescence optics to obtain high-resolution, sharp contrast images. Unlike optical microscopes, confocal microscopes use a focused beam of light laser to scan the entire sample surface at different z-planes. These microscopes are, therefore,...
01:37Super-resolution Fluorescence Microscopy
Super-resolution fluorescence microscopy (SRFM) provides a better resolution than conventional fluorescence microscopy by reducing the point spread function (PSF). PSF is the light intensity distribution from a point that causes it to appear blurred. Due to PSF, each fluorescing point appears bigger than its actual size, and it is the PSF interference of nearby fluorophores that causes the blurred image. Various approaches to achieving higher resolution through SRFM have recently been developed.
01:16Focusing of Light in the Eye
Light rays enter the eye through the cornea, a transparent dome-shaped tissue that is the eye's outermost layer. The cornea bends or refracts, light rays traveling to the pupil. The shape of the cornea determines how much of the light is bent and whether the image will be focused correctly on the retina at the back of the eye. Once the light has passed through both refraction layers, it converges into a single focal point onto a small area. This is where photoreceptors start transforming...