AI Article Synopsis
- Researchers trace molecular hydrogen using carbon monoxide (CO) emissions, with notable detections in quasars at redshifts greater than 2, including one at z = 4.69.
- A new study reports CO emission from quasar SDSS J114816.64 + 525150.3, located at z = 6.42, indicating that heavy-element enrichment in molecular gas can occur quickly in young galaxies from the early Universe.
Article Abstract
Observations of molecular hydrogen in quasar host galaxies at high redshifts provide fundamental constraints on galaxy evolution, because it is out of this molecular gas that stars form. Molecular hydrogen is traced by emission from the carbon monoxide molecule, CO; cold H2 itself is generally not observable. Carbon monoxide has been detected in about ten quasar host galaxies with redshifts z > 2; the record-holder is at z = 4.69 (refs 1-3). Here we report CO emission from the quasar SDSS J114816.64 + 525150.3 (refs 5, 6) at z = 6.42. At that redshift, the Universe was only 1/16 of its present age, and the era of cosmic reionization was just ending. The presence of about 2 x 1010 M\circ of H2 in an object at this time demonstrates that molecular gas enriched with heavy elements can be generated rapidly in the youngest galaxies.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1038/nature01821 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
Probing Impact of Support Pore Diameter on Three-phase Interfaces of Pt/C Catalysts by Molecular Dynamic Simulation.
ACS Appl Mater Interfaces
January 2025
State Key Laboratory of Advanced Chemical Power Sources (Chongqing University), Chongqing 400044, China.
Investigating how the size of carbon support pores influences the three-phase interface of platinum (Pt) particles in fuel cells is essential for enhancing catalyst utilization. This study employed molecular dynamics simulations and density functional theory calculation to examine the effects of mesoporous carbon support size, specifically its pore diameter, on Nafion ionomer distribution, as well as on proton and gas/liquid transport channels, and the utilization of Pt active sites. The findings show that when Pt particles are located within the pores of carbon support (Pt/PC), there is a significant enhancement in the spatial distribution of Nafion ionomer, along with a reduction in encapsulation around the Pt particles, compared to when Pt particles are positioned on the surface or in excessively large pores of the carbon support.
View Article and Find Full Text PDFMolecular Mechanism Behind the Capture of Fluorinated Gases by Metal-Organic Frameworks.
Nanomicro Lett
January 2025
College of Environmental Science and Engineering, State Key Laboratory of Pollution Control and Resource Reuse, Tongji University, Siping Rd 1239, Shanghai, 200092, People's Republic of China.
Fluorinated gases (F-gases) play a vital role in the chemical industry and in the fields of air conditioning, refrigeration, health care, and organic synthesis. However, the direct emission of waste gases containing F-gases into the atmosphere contributes to greenhouse effects and generates toxic substances. Developing porous materials for the energy-efficient capture, separation, and recovery of F-gases is highly desired.
View Article and Find Full Text PDFContinuous Blood Gas Control Based on Active Disturbance Rejection Control During Ex Vivo Porcine Liver Perfusion.
Artif Organs
January 2025
Division of Life Science and Medicine, School of Biomedical Engineering (Suzhou), University of Science and Technology of China, Hefei, China.
Background: Membrane oxygenators facilitate extracorporeal gas exchange, necessitating the monitoring of blood gas. Recent advances in normothermic machine perfusion (NMP) for ex vivo liver offer solutions to the shortage of donor liver. However, maintaining physiological blood gas levels during prolonged NMP is complex and costly.
View Article and Find Full Text PDFiRGD-Targeted Biosynthetic Nanobubbles for Ultrasound Molecular Imaging of Osteosarcoma.
Int J Nanomedicine
January 2025
Department of Ultrasound, The second People's Hospital of Shenzhen, The First Affiliated Hospital of Shenzhen University, Shenzhen, 518061, People's Republic of China.
Purpose: Osteosarcoma is the most common primary malignant tumor of the bone. However, there is a lack of effective means for early diagnosis due to the heterogeneity of tumors and the complexity of tumor microenvironment. αvβ3 integrin, a crucial role in the growth and spread of tumors, is not only an effective biomarker for cancer angiogenesis, but also highly expressed in many tumor cells.
View Article and Find Full Text PDFWhen Photoelectrons Meet Gas Molecules: Determining the Role of Inelastic Scattering in Ambient Pressure X-ray Photoelectron Spectroscopy.
ACS Cent Sci
January 2025
Chemical Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, United States.
Inelastic photoelectron scattering (IPES) by gas molecules, a critical phenomenon observed in ambient pressure X-ray photoelectron spectroscopy (APXPS), complicates spectral interpretation due to kinetic energy loss in the primary spectrum and the appearance of additional features at higher binding energies. In this study, we systematically investigate IPES in various gas environments using APXPS, providing detailed insights into interactions between photoelectrons emitted from solid surfaces and surrounding gas molecules. Core-level XPS spectra of Au, Ag, Zn, and Cu metals were recorded over a wide kinetic energy range in the presence of CO, N, Ar, and H gases, demonstrating the universal nature of IPES across different systems.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!